Posted by: SATYASRINIVAS | May 26, 2007

aptitude11

1. The street of a city are arranged like the lines of a chessboard , there are m street running north and south and n east and west . Find the no. ways in which a man can travel from N.W to the S.E corner, going by the shortest possible distance.

2. How many different arrangement can be made out of the letters in the ex-pression a^3b^2c^4 when written at full length?
Ans. 1260.

3. How many 7-digit numbers exist which are divisible by 9 and whose last but one digit is 5?

4. You continue flipping a coin until the number of heads equals the number of tails. I then award you prize money equal to the number of flips you conducted .How much are you willing to pay me to play this game?

5. Consider those points in 3-space whose three coordinates are all nonnegative integers, not greater than n. Determine the number of straight lines that pass through n of these points.

6 Four figures are to be inserted into a six-page essay, in a given order. One page may contain at most two figures. How many different ways are there to assign page numbers to the figures under these restrictions?

7. How many (unordered) pairs can be formed from positive integers such that, in each pair, the two numbers are coprime and add up to 285?

8. ( 1+ x) ^ n – nx is divisible by
A. x B. x.x C. x.x.x. D. None of these

9. The root of the equation (3-x)^4 + (2-x)^4 = (5-2x)^4 are
a. ALL REAL B. all imaginary C. two real and 2 imaginary D. None of these

10. The greatest integer less than or equal to ( root(2)+1)^6 is
A. 196 B.197 C.198 D.199.

11. How many hundred-digit natural numbers can be formed such that only even digits are used and any two consecutive digits differ by 2?

12. If x1 , x2, x3 are the root of x^3-1=0 , then
A. x1+x2+x3 not equal to 0 B. x1.x2.x3 not equal to 1 C.(x1+x2+x3)^2 = 0 D. None of these

13. How many different ways are there to arrange the numbers 1,2,…,n in a single row such that every number, except the number which occurs first, is preceded by at least one of its original neighbours?

14. There are N people in one room. How big does N have to be until the probability that at least two people in the room have the same birthday is greater than 50 percent? (Same birthday means same month and day, but not necessarily same year.)

15. A 25 meter long wound cable is cut into 2 and 3 meter long pieces. How many different ways can this be done if also the order of pieces of different lengths is taken into account?

16. You are presented with a ladder. At each stage, you may choose to advance either one rung or two rungs. How many different paths are there to climb to any particular rung; i.e. how many unique ways can you climb to rung “n”? After you’ve solved that, generalize. At each stage, you can advance any number of rungs from 1 to K. How many ways are there to climb to rung “n”?

17. Find the no. of rational number m/n where m ,n are relatively prime positive no. satisfying m 5) whose centers form an equilateral triangle. Prove that m = n = 6, and find the angles of ABC.

25. The area of triangle formed by the point (p,2-2p) , (1-p,2p) and (-4-p,6-2p) is 70 units. How many integral values of p are possible.?
A. 2 B. 3 C. 4 D. None of these

26. In a park, 10000 trees have been placed in a square lattice. Determine the maximum number of trees that can be cut down so that from any stump, you cannot see any other stump. (Assume the trees have negligible radius compared to the distance between adjacent trees.)
A. 2500 B.4900 C.6400 D. none of these.

27. A certain city has a circular wall around it, and this wall has four gates pointing north, south, east and west. A house stands outside the city, three miles north of the north gate, and it can just be seen from a point nine miles east of the south gate. The problem is to find the diameter of the wall that surrounds the city.

28. Income of A,B and C are in the ratio 7:10:12 and their expenses in the ratio 8:10:15 . If A saves 20% of his income then B’s saving is what % more/less than that of C’s
A.100% more B. 120% more C. 80% less D. 40% less

29. A triangle ABC has positive integer sides, angle A = 2 angle B and angle C > 90. Find the minimum length of the perimeter of ABC.

30. We have k identical mugs. In an n-storey building, we have to determine the highest floor from which, when a mug is dropped, it still does not break. The experiment we are allowed to do is to drop a mug from a floor of our choice. How many experiments are necessary to solve the problem in any case, for sure? [/glow][/color][/font]

31. The side lengths of a triangle and the diameter of its incircle are 4 consecutive integers in an arithmetic progression. Find all such triangles.

32. We have a 102 * 102 sheet of graph paper and a connected figure of unknown shape consisting of 101 squares. What is the smallest number of copies of the figure, which can be cut out of the square?

33. Between points A and B there are two railroad tracks. One of them is straight and is 4 miles long. The other one is the arc of a circle and is 5 miles long. What is the radius of curvature of the curved track?

34. Number of ordered pair of integer x^2+6x+y^2 = 4 is. A.2 b.4 c.6 d.8.

35. 100 cards are numbered 1 to 100 (each card different) and placed in 3 boxes (at least one card in each box). How many ways can this be done so that if two boxes are selected and a card is taken from each, then the knowledge of their sum alone is always sufficient to identify the third box?

36. A cube is divided into 27 pairwise congruent smaller cubes. Find the maximum number of small cubes that can be stabbed by a straight line.

37. Suppose that you have a table with 8 rows and 8 columns and that the numbers from 1 to 64 are placed in the table in such a way that all the rows and columns add up to the same number. What is this number?

38 A certain shade of gray paint is obtained by mixing 3 parts of white paint with 5 parts of black paint. If 2 gallons of the mixture is needed and the individual colors can be purchased only in one-gallon or half- gallon cans, what is the least amount of paint, in gallons, that must be purchased in order to measure out the portions needed for the mixture?
(A) 2 (B) 2 .5 (C) 3 (D) 3.5 (E) 4

39. What is the least number of digits (including repetitions) needed to express 10^100 in decimal notation?
(A) 4 (B) 100 (C) 101 (D) 1,000 (E) 1,001

40 You are at a track day at your local racecourse in your new Porsche. Because it’s a crowded day at the track, you are only allowed to do two laps. You haven’t driven your car at the track yet, so you took the first lap easy, at 30 miles per hour. But you do want to see what your ridiculous sports car can do. How fast do you have to go on the second lap to end the day with an average speed of 60 miles per hour?

41. A farmer sold 10 sheep at a certain price and 5 others at Rs. 50 less per head : the sum he received for each lot was expressed in rupee by the same 2 digits: find the prices per sheep.

42. If A tell B , that he has thought of a 3 digit no. , in such a way that the sum of all of its digit happens to be a prime no. If based on this information only B tries to find the no. , what is the probabilities that she will find the prime no. in the first guess .

43. The area of intersection of 2 circular discs each of radius r and with the boundary of each disc passing through the center of the other is.

44. An acrobat thief enters an ancient temple, and finds the following scenario:
1. The roof of the temple is 100 meters high.
2. In the roof there are two holes, separated by 1 meter.
3. Through each hole passes a single gold rope, each going all the way to the floor.
4. There is nothing else in the room.
The thief would like to cut and steal as much of the ropes as he can. However, he knows that if he falls from height that is greater than 10 meters, he will die. The only thing in his possession is a knife.
How much length of rope can the acrobat thief get?

45. A 25 meter long wound cable is cut into 2 and 3 meter long pieces. How many different ways can this be done if also the order of pieces of different lengths is taken into account?.

46. A gang of 17 pirates steal a sack of gold coins. When the start dividing the loot among them there was 3 coin left. They start fighting for the 3 left over coins and a pirates was killed. They decided to re-divided the coins, but again there was 10 coin left over. Again they fight and another pirates was killed. However they were third time lucky as this time loot was equally distributed. Now tell the least no. of coin satisfying above condition.

47. The coefficient of x^43 in the product (x-2)(x-5)(x- …….(x-131) is
A. 3087 B.4462 C.5084 D.2926

48. Find all a, b ,c such that the roots of x^3+ax^2+bx-8=0

49. A can hit a target 4 times in 5 shots; B 3 times in 4 shots ; and C 2 times in 3 shots. They all fire shot , find the probabilitiy that 2 shots at least hit.?
Ans. 6/13

50. ABC is an isosceles triangle with AC = BC . The median AD and BE are perp. To each other and intersect at G . If GD = a unit , find the area of the quadrilateral CDGE.

51. A regular octagon with sides 1 unit long is inscribed in a circle . Find the radius of the circle.

52 The pages of a report are numbered consecutively from 1 to 10. If the sum of the page numbers up to and including page number x of the report is equal to one more than the sum of the page numbers following page number x, then x =
(A) 4 (B) 5 (C) 6 (D) 7 (E) 8

53. Two urns contain the same total numbers of balls, some blacks and some whites in each. From each urn are drawn n balls with replacement, where n >= 3. Find the number of drawings and the composition of the two urns so that the probability that all white balls are drawn from the first urn is equal to the probability that the drawing from the second is either all whites or all blacks.

54. Two people agree to meet at a given place between noon and 1 p.m. By agreement, the first one to arrive will wait 15 min for the second, after which he will leave. What is the probability that the meeting actually take place if each of them selects his moment of arrival at random during 12 noon to 1 p.m?

55. A positive no n, not exceeding 100 is chosen in such a way that if n is less than or equal to 50, then probabilities of choosing n is 10 and if n > 50 then it is 3p. What is the probability of choosing a square?

56. What is the greatest area of a rectangle the sum of whose 3 sides is equal = 100.
Ans. 1250 .

57. A plane figure consists of a rectangle and an equilateral triangle constructed on one side of the rectangle . How large is the area of that figure in the term of perimeter.
Ans. 6+ sqrt(3)/132 p^2.

58. A reservoir is shaped like a regular triangle . A ferry boat goes from point A to point B both located on the bank . A cyclist who has to get form A to B can use the ferry boat or to ride along the bank . hat is the least ratio between the speed of cyclist and the speed of the boat at which the use of the boat does not give any gain in time, the location of the point A and B being arbitrary ?
Ans. 2.

59. Find the greatest volume of the cylinder inscribed in the given cone.
Ans. V(R/3) = 4/27 * pie H*R*R

60. In a party with 1982 persons, among any group of four there is at least one person who knows each of the other three. What is the minimum no. of people in the party who know everyone else.

61. In a party with 1982 persons, among any group of four there is at least one person who knows each of the other three. What is the minimum no. of people in the party who know everyone else.

62 A chord PQ is drawn on a circle. If the length of PQ is equal to the radius of the circle, then what is the probability that any line drawn at random from point P through the circle is smaller than PQ A. 1/2 B. 1/3 C. 2/3 D. 3/5.

63 Between 2 station the first, second and the third class fares were fixed in the ratio 8:6:3, but afterwards the first class were reduced by 1/6 and second class by 1/12. In a year no. of first second and third class passenger were in ratio 9:12:26 and the money at the booking counter was 1326. How much was paid by the first class passenger? A. 320 B. 390 C.420 D. None. Of these.

64 . A magician has one hundred cards numbered 1 to 100. He puts them into three boxes, a red one, a white one, and a blue one, so that each box contains at least one card. A member of the audience selects two of the three boxes, chooses one card from each, and announces the sum of the numbers on the chosen cards. Given this sum, the magician identifies the box from which no card has been chosen. How many ways are there to put all the cards into the boxes so that this trick always works? (Two ways are considered different if at least one card is put into a different box.)

65. On a circle are marked 999 points. How many ways are there to assign to each point one of the letters A, B, or C, so that on the arc between any two points marked with the same letter, there are an even number of letters differing from these two?

66. On a train are riding 175 passengers and 2 conductors. Each passenger buys a ticket only after the third time she is asked to do so. The conductors take turns asking a passenger who does not already have a ticket to buy one, doing so until all passengers have bought tickets. How many tickets can the conductor who goes first be sure to sell?

67. Around a table are seated representatives of n countries (n greater than or equal to 2), such that if two representatives are from the same country, their neighbors on the right are from two different countries. Determine, for each n, the maximum number of representatives.

68. 98 points are given on a circle. Maria and Joe take turns drawing a segment between two of the points which have not yet been joined by a segment. The game ends when each point has been used as the endpoint of a segment at least once. The winner is the player who draws the last segment. If Joe goes first, who has a winning strategy?

69. A computer screen shows a 98 * 98 chessboard, colored in the usual way. One can select with a mouse any rectangle with sides on the lines of the chessboard and click the mouse button: therefore, the colors in the selected rectangle switch (black becomes white, white becomes black). Find, the minimum number of mouse clicks needed to make the chessboard all one color.

70. A farmer has four straight pieces of fencing: 1, 2, 3, and 4 yards in length. What is the maximum area he can enclose by connecting the pieces?

71. Somewhere in Northern Asia, groups of 20 man were planning a special group suicide this year. Each of the them will be placed in a random position along a thin, 100 meter long plank of wood which is floating in the sea. Each man is equally likely to be facing either end of the plank. At time t=0, all of them walk forward at a slow speed of 1 meter per minute. If a man bumps into another man, the two both reverse directions. If a man falls off the plank, he drowns. What is the longest time that must elapse till all the man have drowned?

72. I have chosen a number from 1 to 144, inclusive. You may pick a subset (1, 2, .. 144), i.e. U can frame any subset based on AP, GP, or any other thing and then ask me whether my number is in the subset. An answer of “yes” will cost you 2 dollars, an answer of “no” only 1-dollar. What is the smallest amount of money you will need to be sure to find my number?

73. The side lengths of a triangle and the diameter of its incircle are four consecutive integers in an arithmetic progression. Find all such triangles.

74. A 10-digit number is said to be interesting if its digits are all distinct and it is a multiple of 11111. How many interesting integers are there?

75. Two matching decks have 36 cards each; one is shuffled and put on top of the second. For each card of the top deck, we count the number of cards between it and the corresponding card of the second deck. What is the sum of these numbers?

76. A cube of side length n is divided into unit cubes by partitions (each partition separates a pair of adjacent unit cubes). What is the smallest number of partitions that can be removed so that from each cube, one can reach the surface of the cube without passing through a partition?

77. A room has its dimension as 4 ,5 and 6 mt. An ant wants to go from one corner of the room to the diagonally opposite corner. The minimum distance it has to travel is
A.10.1 B. 10.8 C. 10.9 D. 11.2

78. A rumor began to spread one day in a town with a population of 100,000. Within a week, 10,000 people had heard this rumor. Assuming that the rate of increase of the number of people who have heard the rumor is proportional to the number who have NOT yet heard it, how long will it take until half of the population of the town has heard the rumor? A. 44 B.46 C.45 D. none of these

79. A camel must travel 15 miles across a desert to the nearest city. It has 45 bananas but can only carry 15at a time. For every mile camel walks, it needs to eat a banana. What is the maximum number of bananas that can transport to the city? A. 10 B.8 C. 15 D. none of these

80. So far this basketball season, all of Siddhart points have come from two- point and three point field goals. He had scored 43 points. He has made one more than twice as many three pointers as two pointers. How many of each kind of field goal has Siddhart made?

81. Let g (t)=9t^4+6t^2+2. For which value of t is this function a minimum?

82. Consider any two-digit number whose digits are not zero and are not the same. What is the greatest integer that divides evenly the difference between the square of the number and the square of the reverse?
ANS Largest difference = 91^2 – 19^2 = 7920 Hence, the greatest integer is 7920.

83. What is the maximum number of Friday the thirteenths that can occur in any given year?

84. What letter is in the 150th entry of the pattern ABBCCCDDDD……?

85. Tanisha and Richa had lunch at the mall. Tanisha ordered three slices of pizza and two colas. Richa ordered two slices of pizza and three colas. Tanisha’s bill was Rs60.0, and Rachel’s bill was Rs52.5. What was the price of one slice of pizza? What was the price of one colon?

86. An architect plans a room to be 14m x 30m. He wishes to increase both dimensions by the same amount to obtain a room with 141 sq. metres more area. By how much must he increase each dimension?
Ans 3/2, -47/2

87. A geometry teacher drew some quadrilaterals on the chalkboard. There were 5 trapezoids, 12 rectangles, 5 squares, and 8 rhombuses. What is the least number of figures the teacher could have drawn?
Ans 20

88. Given an n x n square board, with n even. Two distinct squares of the board are said to be adjacent if they share a common side, but a square is not adjacent to itself. Find the minimum number of squares that can be marked so that every square (marked or not) is adjacent to at least one marked square.

89. A painted wooden cube, such as a child’s block, is cut into twenty-seven equal pieces. First the saw takes two parallel and vertical cuts through the cube, dividing it into equal thirds; then it takes two additional vertical cuts at 90 degrees to the first ones, dividing the cube into equal ninths. Finally, it takes two parallels and horizontal cuts through the cube, dividing it into twenty-seven cubes. How many of these small cubes are painted on three sides? On two sides? On one side? How many cubes are unpainted?

90. It was claimed that the shepherd was the shepherd of 2000 sheep. The shepherd exclaimed, “I am not the shepherd of two thousand sheep!” Pointing to his flock, he added, “If I had that many sheep plus another flock as large as that, then again half as many as I have out there, I would be the shepherd of two thousand sheep.” How many sheep were in the shepherd’s flock?

91. Leon, who is always in a hurry, walked up an escalator, while it was moving, at the rate of one step per second and reached the top in 20 steps. The next day he climbed two steps per second (skipping none), also while it was moving, and reached the top in thirty-two steps. If the escalator had been stopped, how many steps did the escalator have from the bottom to the top?

92. A, B and C were asked to sell fun-fair tickets priced at $10 each. A sold 1/4 of them. B and C sold the remaining tickets in the ratio 5:7. A received $90 less than C.
What fraction of tickets were sold by C? b) How many tickets did the 3 girls sell altogether?

93.If 500ml of popcorn and 1 box of potato chips cost $1.64, and 250ml of popcorn and 2 boxes of potato chips cost $1.99, and 250ml of popcorn is half the price of 500ml of popcorn, then how much is one box of popcorn?

94.There are three circles, they share a similar area. The similar area is 1/10 of the biggest circle, 1/6 of the second biggest circle, and half of the smallest circle. What is the ratio of the circles?( biggest, second biggest, smallest)

95. Sally and Jeff took 37 hours to complete a whole project. If Sally had worked 5 hours less and Jeff had worked 6 hours more, Jeff would still have put in 2 more hours than Sally. How many hours did Sally put in for the project? (Assume that Sally and Jeff worked separately on their own project.)

96. Mrs Lee purchased 240 rings and some watches. The number of rings was more than the number of watches by 20% of the total number of both items bought. She sold all the watches at $36 each. From the total sale of the rings and the watches, she earned $2240 from her total sale. If each ring was sold at 25% less than the selling price of each watch,
a) find the no. of watches purchased by Mrs Lee, and
b) find the total cost price of all the rings and watches

97. We play the following game with an equilateral triangle of n(n+1)=2 pennies (with n pennies on each side). Initially, all of the pennies are turned heads up. On each turn, we may turn over three pennies which are mutually adjacent; the goal is to make all of the pennies show tails. For which values of n can this be achieved? I. 17 II. 7 III. 8 IV. 6
A. all of the above B. none of the above
C. for more than 2 of the above including IV D. Exactly 2 of them.

98. In a certain town, the block are rectangular with stress running East-West, the avenues North-South. A man wishes to go from one corner to another m block East, n block North. In how many ways the shortest path can be achieved.

99. Two players take turns drawing a card at random from a deck of four cards labeled 1,2,3,4. The game stops as soon as the sum of the numbers that have appeared since the start of the game is divisible by 3, and the player who drew the last card is the winner. What is the probability that the player who goes first wins?

100. We are given 1997 distinct positive integers, any 10 of which have the same least common multiple. Find the maximum possible number of pairwise coprime numbers among them.
Ans 9.

101. A rectangular strip of paper 3 centimeters wide and of infinite length is folded exactly once. What is the least possible area of the region where the paper covers itself?
A. 4.5 B. 4 C. 3.45 D. 5.4

102. A company has 50000 employees. For each employee, the sum of the numbers of his immediate superiors and of his immediate inferiors is 7. On Monday, each worker issues an order and gives copies of it to each of his immediate inferiors (if he has any). Each day thereafter, each worker takes all of the orders he received on the previous day and either gives copies of them to all of his immediate inferiors if he has any, or otherwise carries them out himself. It turns out that on Friday, no orders are given. The least employees who have no immediate superiors are. A. 97 B. 518 C.216 D. none of these.

103.The numbers from 1 to 37 are written in a line so that each number divides the sum of the previous numbers. If the first number is 37 and the second number is 1, what is the third number?

104. The centre of the circumcircle of triangle ABC with angle C = 60 is O and its radius is 2 . Find the radius of the circle that touches AO , BO and the minor arc AB.

105 . ABC is an equilateral triangle in which B is extended to K such that CK = ½ BC. Find AK^2 * 1/ CK^2
A. 3 B. 7 C. 5 D. 6

106. Let S be the set of prime numbers bigger than 100 but smaller than 150. Let n be the product of all the numbers in the set S . Which of the following statement is FALSE?
A. 5 does not divide n B. 17 divide n. C. n is an odd number D. n is a product of distinct primes.

107. A cube of side ‘a’ is converted into a sphere by adding clay on all the faces of the cube. The minimum volume of clay required is
Ans. a^3( pie * sqrt(3)/2 – 1) .

108. The product of all integer from -129……….+130, ends inclusive , then which of the following values is closet to the result? A. 65^65 B. 9^2 C. -65^65 20^12.

109. Four people, A, B, C, and D, are on one side of a bridge, and they all want to cross the bridge. However, it’s late at night, so you can’t cross without a flashlight. They only have one flashlight. Also, the bridge is only strong enough to support the weight of two people at once. The four people all walk at different speeds: A takes 1 minute to cross the bridge, B takes 2 minutes, C takes 5 minutes, and D takes 10 minutes. When two people cross together, sharing the flashlight, they walk at the slower person’s rate. How quickly can the four cross the bridge?

110. A cube is divided into 27 pairwise congruent smaller cubes. Find the maximum number of small cubes that can be stabbed by a straight line.

1)When a four digit number is multiplied by N,the four digit number repeats itself to give an 8 digit number .If four digit number has all distinct digits then N is a multiple of ?
a)11 b) 37 c)73 d) 27
Ans 73

2)Find the greatest and least values of
f(x) = x^4 +x^2+5 / (x^2+1)(x^2+1)
for real x
a)5,0.95 b ) 5,-1 c)4,0 d)3,2
Ans a

3)Out of m persons sitting at a round table in how many ways no two of the persons
A,B, C are sitting together?
a)m(m-1)(m-2) b)m(m-2)(m-3) c)m(m-4)(m-5) d)m(m-1)
Ans c

4)A bookworm starts eating pages of a book from a certain page number in ascending order of page numbers without missing a single page between the first and last pages eaten by it .When it finished with its job it counts the sum of the page numbers of
all the pages eaten and finds that the sum is 198.Find the page number where it stopped eating?The cover page of the book is page number 1 and the worm always eats both sides of a sheet.
a)11 b) 22 c) 33 d ) 44
Ans c

5)The number from 1 to 33 are written side by side as follows : 123456………..33.If this number is divided by 9 what is the remainder?
a)0 b)1 c)3 d) 6
Ans c

6) A positive three digit number X is such,when divided in two unequal three digit number,the larger part is the aritmetic mean of X and the smaller part.How many values can X take?
a)300 b)234 c)198 d)None
Ans b

7)A 101 digit number 222………2X3…333 is formed by repeating the digit 2,50 times followed by the digit X and then repeating the digit 3,50 times.The number is a multiple of 7.Find the value of X.?
a)2 b)3 c ) 4 d ) 5
Ans d

8) There are ten coin making machine.Nine of them produces coins of 10 gm each while the tenth machine produces coins with 11 gm weight . If one has a weight measuring instrument to measure weight in grams,how many minimum number of readings are required
to determine which machine produces heavier coins?
a)1 b)3 c)4 d)None of these
Ans a

9)A student is solving a maths problem.He attempts to solve a particular problem where he has to determine the sum of the squares of the roots of the given polynomial.
The print having faded over time,he can see only 3 terms of the fifth degree polynomial
x^5-11x^4+….-13=0 is all that is visible.He still manages to find the answers What is it given that -1 is the root and all other roots are integers?
1)171 2)173 3)169 4)None
Ans 2

10) The number 444444….(999 times) is definitely divisible by:
a)22 b)44 c)222 d)444
Ans c

11)If a three digit number is divided into three two digit numbers and if all these three two digit numbers from an A.P. with a common difference of 20.How many three digit numbers satisfy this condition?
a)54 b)45 c)46 d) 55
Ans c

12) If first 23 terms of the series 1,11,111 are added together ,what digit would occupy the thousands place?
a)3 b)0 c)9 d)2
Ans d

13)A chord is drawn arbitrarily in a given circle.What is the probability that the length of the chord is less than or equal to the radius of the circle?
a)0.5 b)0.25 c)0 d)0.33
Ans d

14) Ravi,Deepak and Amod started out on a 100 mile journey.Ravi and Deepak went by car at the rate of 25mph,while Amod walked at the rate of 5 mph.After a certain distance,Deepak got off and started walking at 5 mph,while Ravi drove back for Amod and
got him to the destination in the car at the same time that Deepak arrived.
Q)What is the time taken by Amod to finish the journey?
a)6 b)7 c)8 d)None
Ans c
Q)What was the total distance(in miles) travelled by Ravi?
a)100 b)200 c)250 d)150
Ans b

15)How many natural numbers are factors of 7560 and multiples of 14?
a)20 b)22 c)24 d)28
Ans c

16)Definition:If a,k and n are positive integers with k>1,and n=k*a ,then a is called
proper divisor of n.How many positive integers less than 54 are equal to the product of their proper divisors?
a)1 b)8 c)10 d)14
Ans d

17) Given that A is a six digit number with unit digit of 1,and B is a natural number which is the fourth root of A,what is the largest possible value of B?
a)23 b)29 c)31 d)37
Ans 31

18)How many integers greater than 40,00,000 and less than 90,00,000 are perfect squares?
a)100 b)999 c)1000 d)1999

19)Six integers are selected from 1 to 100 in such a way that the smallest positive difference between any two of them is as large as possible.What is this difference?
a)16 b)17 c)19 d)20

20)How many different points in the xy plane are at a distance of 5 from the origin and have coordinates (a,b) ,where a and b are integers?
a)4 b)6 c)8 d) 12

A survey was conducted in a city to determine the choice of channel (DD, BBC
and CNN) among viewers in viewing the news. The viewership for these three
channels is 80, 22 and 15 percent respectively. Five percent of the
respondents do not view news at all.

Ques: What is the maximum percent of viewers who watch all the three
channels?

1)22 2)15 3)11

ANS: We know that
n(A)+n(B)+n(C)-n(AintersectionB)-n(BintersectionC)-n(AintersectionC)- (2 x
All three) = 95
To have a max. intersection, the intersecting pairs must be 0
Or, 80+22+15 -2X = 95
Or, x=11

A fruit vendor bought 100 pounds of berries for
> > $2.00 per pound and
> > expected to double his investment by selling the
> > berries for $4.00
> > per pound at an open-air market. The vendor only
> > managed to sell 50
> > pounds of berries the first day and he sold the
> > remainder on the
> > second day. The fresh berries had a content of 99%
> > water, but because
> > of the hot weather, the berries dehydrated and
> > contained only 98%
> > water on the second day. How much profit did the
> > vendor make?

Rohit Arora is absolutely right about the first day .. so whatever he
sold the second day is the profit. But explanation for second day is
wrong as the weight of berry can’t increase .. instead water has to
dry out..

Initially vendor had 100 pounds in all at 99% which means he had 99
pounds of water and 1 pound of actual berry.

Now at the end of the first day the vendor is left with 50 pound(half
of 100) in all i.e. he had 49.5 pounds of water(half of initial) and
0.5 pound of berry(half of initial). [Remeber this is still the first
day so %age of water in berry should be 99% which is actually correct
as 49.5/50 * 100 = 99% ]

Now let the water in berry be x pounds (after water dries out a bit)
also weight of actual berry is 0.5 pound (as this will not dry out)
Also it is given that percentage of water on second day is 98%

=> Water/(Water+Berry) = 98/100
=> x/(x+0.5) = 98/100
=> 100x = 98(x+0.5)
=> 100x = 98x + 49
=> 2x = 49
=> x = 24.5 pounds

So on second day … water = 24.5 pounds and actual berry = 0.5 pounds
(as this will not dry out) => total berry = 25 pounds

Now this berry is sold at $4 per pound which gives a total profit of
25*4 = $100 which is the answer.
=>

1. A club with x members is organised into 4 committees according to the following rules :
(i) Each member belongs to exactly 2 committees
(ii) Each pair of committees has exactly 1 member in common.
Then find the value of x….?

2.The no. of integer lying between 3000 and 8000(both included) that have at least 2 digits equal.

3.The coefficient of x^4 in the expansion of (1+x-2x^2)^7 is .

4. A closet has pairs of shoes. The no ways in which 4 shoes can be chosen from it so that there be no complete pairs.

5. Distance passed over by a pendulum bob in successive swing are 16, 12, 9, 6.75..cm. Then the total distanced traversed b the bob before it come to rest is (in cm) A. 60 B. 64 C.65 D.67.

6 The point (2,1), (8,5) and (x,7) lie on a straight line , find the value of x..?.

7.Eight singers participate in an art festival where m songs are performed. Each song is performed by 4 singers, and each pair of singers performs together in the same number of songs. Find the smallest m for which this is possible. A. 12 B.14 C.16 D.18

When two fat fish of identical volume were placed inside the tank, the water level rose to a height of 25 cm.
(a) What is the volume of one fat fish?
(b) How many small turtles of volume 250 would be needed to replace the fish?

10. In D ABC, ÐC = 90, ÐA = 30 and BC = 1. Find the minimum of the length of the longest side of a triangle inscribed in ABC (that is, one such that each side of ABC contains a different vertex of the triangle).

11. Starting at (1, 1), a stone is moved in the coordinate plane according to the following rules:
(i) From any point (a, b), the stone can move to (2a, b) or (a, 2b).
(ii) From any point (a, b), the stone can move to (a-b, b) if a > b, or to (a, b-a) if a 5) whose centers form an equilateral triangle. Prove that m = n = 6, and find the angles of ABC.25. Find all real numbers x such that X [x [x [x]]] = 88:

26. Two players take turns drawing a card at random from a deck of four cards labeled 1,2,3,4. The game stops as soon as the sum of the numbers that have appeared since the start of the game is divisible by 3, and the player who drew the last card is the
winner. What is the probability that the player who goes first wins?

27. Find all triples (x, y, n) of positive integers with gcd(x, n + 1) = 1 such that x^n + 1 = y^n+1.

28. The point P lies inside an equilateral triangle and its distances to the three vertices are 3, 4, 5. Find the area of the triangle.

29. A triangle ABC has positive integer sides, angle A = 2 angle B and angle C > 90. Find the minimum length of the perimeter of ABC.

30. A country has 1998 airports connected by some direct flights. For any three airports, some two are not connected by a direct flight. What is the maximum number of direct flights that can be offered?

31. The side lengths of a triangle and the diameter of its incircle are 4 consecutive integers in an arithmetic progression. Find all such triangles.

32. We have a 102 * 102 sheet of graph paper and a connected figure of unknown shape consisting of 101 squares. What is the smallest number of copies of the figure, which can be cut out of the square?

33. Remainder when 3^37 is divided by 79. ? A.78 b.1 c.2 d.35

34. Number of ordered pair of integer x^2+6x+y^2 = 4 is. A.2 b.4 c.6 d.8.

35. Remainder when 3^2002 + 7^2002 + 2002 is divided by 29.

36. a1, … , a8 are reals, not all zero. Let cn = a1n + a2n + … + a8n for n = 1, 2, 3, … . Given that an infinite number of cn are zero, find all n for which cn is zero.

37. In how many ways can Rs. 18.75 be paid in exactly 85 coins , consists of 50 paise, 25 p and 10p coins.

38. In a certain community consisting of p persons , a % can read and write : of the males alone b % , and of the females alone c % can write : find the no. of males and females in the community (in a, b, c and p terms) .

39. A no. of 3 digit in base 7 when expressed in base 9 has it’s digits reversed in order : find the no.

40 A man has to take a plot of land fronting a street : the plot is to be rectangular , and 3 times it’s frontage added to 2 it’s depth is to be 26 metres. What is the greatest no of square metres he can take.

41. A farmer sold 10 sheep at a certain price and 5 others at Rs. 50 less per head : the sum he received for each lot was expressed in rupee by the same 2 digits: find the prices per sheep.

42. If A tell B , that he has thought of a 3 digit no. , in such a way that the sum of all of its digit happens to be a prime no. If based on this information only B tries to find the no. , what is the probabilities that she will find the prime no. in
the first guess .

43. The area of intersection of 2 circular discs each of radius r and with the boundary of each disc passing through the center of the other is ..

44. Find 3 consecutive integer each divisible by a square greater than 1.

45.Find the 3 consecutive no , the first of which is divisible by a square , the second by a cube and third by a fourth power .

46. A gang of 17 pirates steal a sack of gold coins. When the start dividing the loot among them there was 3 coin left. They start fighting for the 3 left over coins and a pirates was killed. They decided to re-divided the coins , but again there was 10
coin left over. Again the fight and another pirates was killed. However they were third time lucky as this time loot was equally distributed. Now tell the least no. of coin satisfying above condition.

47. Find all prime for which the quotient (2^p-1 – 1)/p is a square.

48. find all a, b ,c such that the roots of x^3+ax^2+bx-8=0

49. Find all pairs of integer (x,) such that (x-1)^2=(x+1)^2+(y+1)^2.

50. ABC is an isosceles triangle with AC = BC . The median AD and BE are perp. To each other and intersect at G . If GD = a unit , find the area of the quadrilateral CDGE.

51 A regular octagon with sides 1 unit long is inscribed in a circle . Find the radius of the circle.

52 A regular octagon with sides 1 unit long is circumscribed in a circle . Find the radius of the circle.

53. In a recent exam, your teacher asked 2 difficult questions : “Eugenia ,which is further north, Venice or Vladivoski?” and “What is the latitude and longitude of the north pole?”.Of the class, 33 1\3% of the students were wrong on the latitude question , but only 25% missed the other one. 20% answered both questions incorrectly. 37 students answered both questions correctly . How many students took the examination?

54. Two people agree to meet at a given place between noon and 1 p.m. By agreement, the first one to arrive will wait 15 min for the second, after which he will leave. What is the probability that the meeting actually take place if each of them selects his
moment of arrival at random during 12 noon to 1 p.m?

55. A positive no n, not exceeding 100 is chosen in such a way that if n is less than or equal to 50, then probabilities of choosing n is 10 and if n > 50 then it is 3p. What is the probability of choosing a square?

56. What is the greatest area of a rectangle th esum of whose 3 sides is equal = 100.
Ans. 1250 .

57. A plane figure consists of a rectangle and an equaliteral triangle constructed on one side of the rectangle . How large is the area of that figure in the term of perimeter.
Ans. 6+ sqrt(3)/132 p^2.

58. A reservoir is shaped like a regular triangle . A ferry boat goes from point A to point B both located on the bank . A cyclist who has to get form A to B can use the ferry boat or to ride along the bank . hat is the least ratio between the speed of
cyclist and the speed of the boat at which the use of the boat does not give any gain in time, the location of the point A and B being arbitrary ?
Ans. 2.

59. Find the greatest volume of the cylinder inscribred in the given cone.
Ans. V(R/3) = 4/27 * pie H*R*R

60. In a party with 1982 persons, among any group of four there is at least one person who knows each of the other three. What is the minimum no. of people in the party who know everyone else.
Ans. ??(not have)

61. In a party with 1982 persons, among any group of four there is at least one person who knows each of the other three. What is the minimum no. of people in the party who know everyone else.

62 A chord PQ is drawn on a circle. If the length of PQ is equal to the radius of the circle, then what is the probability that any line drawn at random from point P through the circle is smaller than PQ A. 1/2 B. 1/3 C. 2/3 D. 3/5.

63 Between 2 station the first, second and the third class fares were fixed in the ratio 8:6:3, but afterwards the first class were reduced by 1/6 and second class by 1/12. In a year no. of first second and third class passenger were in ratio 9:12:26 and
the money at the booking counter was 1326. How much was paid by the first class passenger? A. 320 B. 390 C.420 D. None. Of these.

64 . A magician has one hundred cards numbered 1 to 100. He puts them into three boxes, a red one, a white one, and a blue one, so that each box contains at least one card. A member of the audience selects two of the three boxes, chooses one card from
each, and announces the sum of the numbers on the chosen cards. Given this sum, the magician identifies the box from which no card has been chosen. How many ways are there to put all the cards into the boxes so that this trick always works? (Two ways
are considered different if at least one card is put into a different box.)

65. On a circle are marked 999 points. How many ways are there to assign to each point one of the letters A, B, or C, so that on the arc between any two points marked with the same letter, there are an even number of letters differing from these two

66. On a train are riding 175 passengers and 2 conductors. Each passenger buys a ticket only after the third time she is asked to do so. The conductors take turns asking a passenger who does not already have a ticket to buy one, doing so until all passengers have bought tickets. How many tickets can the conductor who goes first be sure to sell?

67. Around a table are seated representatives of n countries (n greater than or equal to 2), such that if two representatives are from the same country, their neighbors on the right are from two different countries. Determine, for each n, the maximum number of representatives.

—————————————————————————————Q.2 A ladder lies against a wall. The top of the ladder reaches 8 ft. above the ground. When the ladder slips two metres away from the wall, the top of the ladder touches the foot of the wall. The length of the ladder is
1) 15 2) 17 3) 8 4) 10

Q.3 A takes 4 days to do a work. B takes twice as long as A. C takes twice as long as B and D takes twice as long as C. They are made in groups of two. One of the groups takes two third of the time taken by second pair. What is the combination of the first pair?

1) A,C 2) A,D 3) B,C 4) B,D

Q.4 A student got marks in the ratio 6:7:8:9:10 in five subjects having equal maximum marks. In all, he scored 60% marks. In how many subjects, he got more than 50% ?

1) 4 2) 5 3) 3 4) None of these

Q.5 What is the least value of x for which expression x3 – 7×2 + 11x – 5 gives positive quantity?

1) 4 2) 5 3) 8 4) None of these

Q.9 Ram is having 158 coins of one rupee. He puts it in different bags, so that he can hand over the cash of any denomination required between Rs. 1 to Rs. 158. What is the least no. of bags required ?

1) 11 2) 13 3) 15 4) None of these

Q.10 Train X starts from A towards B. At same time, train Y start from B towards A. Train X travels at speed of 70 kmph and Y travels at 50 kmph. While X does not stop anywhere on the way, the train Y stops at station C in between at 60km from B for 15 minutes. At what distance from A they would meet

1) 115km 2) 112km 3) 120km 4) None of these

Q.11 There are three classes X,Y and Z. Average of class X is 83. Average of Class Y is 76. Average of class Z is 85. Average of class X and Y is 79, average of class Y and Z is 81. Find average of three Classes.

1) 81 2) 81.5 3) 82 4) 84

Q.12 There are five nos. a,b,c,d,e having value of 2,5,6,10,4, not necessarily in this order. We have following clues

1) c + a = e 2) e + a = d 3) b-d = d
Which of the following is true ?
1) 10-5 = b-d 2) 4 + 6 = a+e 3) 4-2 = b-d 4) None of these.

Q.13 How many 5 digit different nos. can be formed which is divisible by 4 from the digits 1,2,3,4,5,6 without repetition.
1)144 2)168 3)192 4)None of these

Q.14 All the pages of a book starting from page 1 are summed. One of the pages has been added twice, and the total thus obtained is 1000. Which is the page that has been added twice ?

1) 10 2) 12 3) 14 4) None of these.

Q.15 In a certain system product of 44 X 11 is represented as 2124 find how 1453 can be represented in decimal system ?

1)248 2) 346 3) 393 4) 410

Q.16 All positive consecutive integers starting from 1 were written on the blackboard. One of the students entered the class and erased one of the numbers. Now the average of the remaining numbers is 35 7/17.The erased number is _______.

1)17 2)8 3)9 4)None of these

Q.18 In a four digit number, the sum of digits in the first and fourth place is twice the sum of the digits in the third and fourth place. The difference in the first and third digit is equal to the second digit. What is the digit in the third place?

1) 5 2) 4 3) 3 4) 1

Q.19 A person had to multiply two numbers. Instead of multiplying by 35, the person multiplied by 53, and the product went up by 540.What was the raised product?

1) 780 2) 1040 3) 1590 4) None of these

Q.20 Euclid had a triangle in his mind .The longest side is 20 and the other side is 10.Area of the triangle is 80.The third side is__

1) root 260 2) root 240 3) root 250 4)root 210

Q.21 09/12/2001 is Sunday. What was the day on 09/12/9071?

1) Thursday 2) Wednesday 3) Saturday 4) Sunday

Q.22 In a fibonacci series, difference between squares of 6th and 7th terms was 517. What is the 8th term.

1) 32 2) 65 3) 83 4) None of these

Q.23 There is a circular field having four doors in North, East, West and South. A person walks 3 meters from the North door. Another person comes out of the South door and walks 9 meter towards East so that he is just able to see the first man. What is the diameter of the field.

1) 12 2) 15 3) 9 4) None of these.

Q.25 Ram has 128 boxes with him. He has to put atleast 120 oranges in one box and 144 at the most. Find the least number of boxes which will have the same number of oranges.

1) 5 2) 6 3) 103 4) Can’t determine.

Q.26 There are two persons A and B who joined an organization on 1st Jan 1970. A joined at Rs. 300 and annual increment of Rs.30. B gets salary of Rs. 200 and hike of Rs. 50 per six month. Find the total amount distributed at the end of 31st December 1979.

1) 91200 2) 92800 3) 97200 4) None of these

Q.29 If X and Y are positive integers and X + Y = 1, what is the least value of

(X + 1/X)2 + (Y+1/Y)2 ?

1) 24 2) 12.5 3) 20 4) None of these

Q.30 2 b and c> d and abcd =1 ,then which of the following is correct?

1) bd ³ ac 2) a+c > b+d 3) a2 b 5 and y 1 2) 4x > 5y 3) –4x 0 2) (x-z)y2 > 0 3) (x-y)2z > 0 4) None of these

Q.40 There is a rectangular field of length 60 m and width 20 m. A path of uniform width and area 516 sq m surrounds the field. Find the width of path

1) 1 2) 2 3) 3 4) 4

Q.41 If abcd = 1 then the minimum value of (1+a)(1+b) (1+c) (1+d) is __________

1) 8 2) 16 3) 4 4) None of these

Q no.42 -44 are based on the following data:

A player X played an inning such that

r1=Scores of completed innings.

r2=Scores of incomplete innings.

n1= number of completed innings.

n2=number of incomplete innings.

B=r1+r2 / n1 C=r1/n1 + max { 0,r2-r1/n2}

D= r1+r2/ n1+n2

Q.42 Which of the following holds?

1) C ³ B ³ D 2) D ³ B ³ C 3) B ³ C ³ D 4) None of these.

Q.43 If B=100 and in next innings he scored 45 not out, then which of the following holds?

1) B>C 2) C>B 3) C>D 4) None of these

Q.44 If total number of matches played were 20 and the score was 620,which of the following is true?

1) B=31 2) D=31 3) C>D 4) None of these.

Q.45 What is the minimum value of value of x for which the expression x3-5×2+11x-5 gives positive values?

1) 5 2) 8 3) 4 4) None of these.

Q.46 One boy while solving a Quadratic equation takes the constant term wrong and gets the roots (4,3). Another boy takes the coefficient of x wrong and gets the roots (2,3). What are the actual roots?

1) (6,1) 2) (-4,3) 3) (2,-3) 4) None of these.

Q.47 If A,B,C are running a race A beats B by 12m while B beats C by 8 m. What is the length of the track ?

1) 48 2) 30 3) 50 4) None of these.

Q.48 The difference in the money between A and B is Rs.1450.C has money twice of B and difference in the money between A and C is Rs.700.So the amount with A is?

1) 750 Rs. 2) 2200Rs. 3) 800Rs. 4) None of these.

Q.49 P, Q and S are moving on a circular stadium of circumference 2100 m. When P completes one round, Q is still 700 m behind. When S completes one round, Q is 300 m ahead of him. How far from the starting point three of them will meet for the first time ?

1) 168 2) 2568 3) 2100 4) None of these

Q.50 x, y, z are distinct integers such as x is positive, y is lesser than x and z is more than x and y. Then which of the following is true ?

1) x y³ 0 2) x-y > 0 3) x y z >0 4) None of these

1. (1)
2. (2)
3. (2)
4. (1)
5. (4)
6. (1)
7. (1)
8. (4)
9. (4)
10. (2)

11. (2)
12. (3)
13. (3)
14.(1)
15.(3)
16.(4)
17.(2)
18.(2)
19.(3)
20. (1)

21.(1)
22.(4)
23. (3)
24. (3)
25. (4)
26. (4)
27. (2)
28. (1)
29. (2)
30.(3)

31. (2)
32. (4)
33. (1)
34. (2)
35. (2)
36. (4)
37. (2)
38. (3)
39. (3)
40.(3)

41. (2)
42. (3)
43. (1)
44. (2)
45. (4)
46. (1)
47. (1)
48. (2)
49. (1)
50.(2)
—————————————————————————————Question 4 the day: April 29, 2002
Train A traveling at 60 km/hr leaves Mumbai for Delhi at 6 P.M. Train B traveling at 90 km/hr also leaves Mumbai for Delhi at 9 P.M. Train C leaves Delhi for Mumbai at 9 P.M. If all three trains meet at the same time between Mumbai and Delhi, what is the speed of Train C if the distance between Delhi and Mumbai is 1260 kms?
(1) 60 km/hr (2) 90 km/hr (3) 120 km/hr (4) 135 km/hr
Correct Answer – (3)

Solution:

All three trains meet at the same time between Delhi and Mumbai. Which means Train A and Train B are at the same point at that time. This will happen when Train B is overtaking Train A.

Train A starts 3 hours before Train B. Therefore, by the time Train B leaves Mumbai, Train A has covered 3 * 60 = 180 kms.

The relative speed between Train A and Train B = 90 – 60 = 30 kmph. Therefore, Train B will overtake Train A in = 6 hours from the time Train B leaves Mumbai. That is at 3 A.M, Train B will overtake Train A. The point between Mumbai and Delhi at which Train B overtakes Train A will be 6*90=540 kms from Mumbai.

Train C will also be at that point at 3 A.M while Train B is overtaking Train A. And Train C would have travelled 1260-540 = 720 kms in these 6 hours. Therefore, the speed of Train C = = 120 km/hr.

As far as Speed, Time and Distance chapter is concerned, you need to know exactly three basic concepts.
Concept 1:
Distance = Speed * Time

Just ensure that the units that you use are all in sync with each other. That is if you are measuring speed in km/hr, then make sure that the distance is calculated in km and time in hours. Else convert the units appropriately.
Concept 2:
Average Speed = Total Distance Traveled
Total Time Taken
Concept 3:
Relative Speed of two objects moving at speeds S1 and S2 in the same direction = | S1 – S2 | Relative Speed of two objects moving at speeds S1 and S2 in opposite directions = S1 + S2

Question
Two trains, 200 and 160 meters long take a minute to cross each other while traveling in the same direction and take only 10 seconds when they cross in opposite directions. What are the speeds at which the trains are traveling?
(1) 21 m/s; 15 m/s (2) 30 m/s; 24 m/s (3) 18 m/s; 27 m/s (4) 15 m/s; 24 m/s
Correct Answer – (1)
Solution
The distance covered by the two trains when they cross each other completely = sum of the length of both the trains.

Distance covered = 200 + 160 = 360 meters.

Let Train 1 be traveling at S1 m/sec and Train 2 be traveling at S2 m/sec.

When the trains are traveling in the same direction, their relative speeds = | S1 – S2 | m/sec.
When the trains are traveling in opposite directions, their relative speeds = S1 + S2 m/sec.

The relative speeds of the train when they are traveling in the same direction = = = 6 m/sec = S1 – S2 –- (1)

The relative speed when the trains are traveling at opposite directions = = = 36 m/sec = S1 + S2. –- (2)

Solving eqn (1) and eqn (2) we get S1 = 21 m/sec and S2 = 15 m/sec.
Question
An express train traveling at 72 km/hr speed crosses a goods train traveling at 45 km/hr speed in the opposite direction in half a minute. Alternatively, if the express train were to overtake the goods train, how long will it take to accomplish the task. Assume that the trains continue to travel at the same respective speeds as mentioned in case 1.
(1) Cannot be determined (2) 30 seconds (3) 150 seconds (4) 130 seconds
Correct Answer – (4)
Solution
When two train cross each other in the opposite direction or when a train overtakes another train, the distance covered by the express train is equal to the sum of the lengths of both the trains.

Case 1. When the trains travel in opposite direction

Distance traveled = sum of lengths of the two trains = Relative speeds of the trains * time taken.

In this case relative speeds = 72 + 45 = 117 km/hr (Relative speed when two objects travel in opposite direction = sum of the individual speeds).

Time taken = half a minute = 30 seconds.

As the speed is in km/hr and time is in seconds, let us convert the speed also into m/sec to ensure congruency in the units.

117 km/hr = = m/sec.
Therefore, distance covered = sum of the lengths of the two trains = = 975 metres.
Case 2. When the trains are traveling in the same direction – that is when the express train is overtaking the goods train

Distance traveled = sum of the lengths of the two trains = Relative speed * Time taken

Relative speed = (72 – 45) = 27 km/hr (When two objects travel in the same direction – their relative speeds is equal to the difference between their individual speeds)

As the lengths of the two trains will remain the same irrespective of their direction of travel, the distance traveled will be the same in both the cases = 975 m.

Converting 27 km/hr into m/sec, we get = m/sec.

975 m = * time taken (in seconds)

time taken = = 130 seconds.

P.s if you know the conversion from km/hr to m/sec (which 1 km/hr = 5/18 m/sec), you can actually solve this problem in about 25 to 30 seconds.
The question for the day is from the topic – boats and streams. Problems in boats and streams use to important concepts.

The medium in which the boat moves, water in a stream, also moves in a particular direction. Therefore, the effective speed of the boat for an observer standing on the banks of the river will depend on the direction in which the boat moves. If the boat moves along the stream in the direction of flow of water, then the boat is said to be traveling downstream. The effective speed of the boat as observed by a stationary observer standing on the banks will be the sum of the speed of the boat in still water and the speed of the stream.

On the contrary, if the boat moves in the direction opposite to the direction of the stream, then the effective speed of the boat as observed by a stationary observer standing on the banks of the river will be the speed of the boat in still water minus the speed of the stream. In this case, the boat is said to travel upstream.
Question
A boat travels from point A to point B upstream and returns from point B to point A downstream. If the round trip takes the boat 5 hours and the distance between point A and point B is 120 kms and the speed of the stream is 10 km/hr, how long did the upstream journey take?
(1) 2 hours 40 minutes (2) 2 hours 24 minutes (3) 3 hours (4) 2 hours
Correct Answer – (3)
Solution
The total distance covered by the boat during the round trip = 120 * 2 = 240 kms. The boat took 5 hours to undertake the round trip. Therefore, the average speed of travel = = 48 km/hr.

Let U be the speed of the boat upstream. Let B be the speed of the boat in still water and D be the speed of the boat downstream.

Upstream speed of boat = Still water speed – speed of stream
= B – 10.

Downstream speed of boat = Still water speed + speed of stream
= B + 10.

As the distance between A and B is the same as the distance between B and A, the average speed of travel for the round trip is given by = 48 km/hr (two different speeds equal distances in each of the speeds, then the average speed is given by the formula given above)

= 48.

Solving for B, we get B2 – 48B – 100 = 0
==> B2 – 50B + 2B – 100 = 0
=> B = 50 or B = -2. As speed cannot be negative, we get the speed of the boat in still water = 50 km/hr.

Therefore, the upstream speed = 50 – 10 = 40 km/hr.
Time taken to travel upstream = = 3 hours.
Question 4 the day: June 24, 2002
The question for the day is from the topic – Speed, Time and Distance.
A train travels at an average speed of 90 km/hr without any stoppages. However, its average speed decrease to 60km/hr on account of stoppages. On an average, how many minutes per hour does the train stop?
(1) 12 minutes (2) 18 minutes (3) 24 minutes (4) 20 minutes
Correct Answer – (4)

Solution:

If it travelled at 90 km / hr, it would have crossed 90 kms in an hour. However, it covered only 60 kms due to stoppages.

The distance it covered decreased by 1/3 or it covered only 2/3rd of the distance that it can cover for which the traveling time would have been 2/3rd of an hour. The remaining 1/3rd of an hour was spent in stoppages. Therefore, the train stops on an average for 20 minutes every hour.
Question 4 the day: June 25, 2002
The question for the day is from the topic – Speed, Time and Distance.

There are certain standard formula and rules that exist in the chapter speed, time and distance. It is important that you understand how these rules work (the logic behind the rules) and preferably memorize them. This way it will take very little time during CAT when you actually solve these types of questions.
Two trains A and B start simultaneously from stations X and Y towards each other respectively. After meeting at a point between X and Y, train A reaches station Y in 9 hours and train B reaches station X in 4 hours from the time they have met each other. If the speed of train A is 36 km/hr, what is the speed of train B?
(1) 24 km/hr (2) 54 km/hr (3) 81 km/hr (4) 16 km/hr
Correct Answer – (2)

Solution:

The ratio of the speed of the two trains A and B is given by

, where b is the time taken by train B to reach its destination after meeting train A and a is the time taken by train A to reach its destination after meeting train B.

In this case,
=> Speed of train B = * Speed of train A = * 36 = 54 km/hr
An interesting exercise that you can try is to find out how this formula was derived. You can check out for the derivation tomorrow on our site to verify if your approach was right.
Question 4 the day: July 5, 2002
A man goes from city A to city B situated 60 kms apart by a boat. His onward journey was with the stream while the return journey was an upstream journey. It took him four and half hours to complete the round trip. If the speed of the stream is 10 km/hr, how long did it take him to complete the onward journey?
(1) 3 hours (2) 3.5 hours (3) 2.25 hours (4) 1.5 hours
Correct Answer – (4)

Solution:

The average speed for the round trip = km/hr
Let the speed during the onward journey be ‘D’ km/hr. Let the speed of the boat in still water be ‘B’ km/hr.

Therefore, D = B + S => D = B + 10 (As the speed of the stream is 10 km/hr).

Let the speed during the return journey be ‘U’ km/hr.
Therefore, U = B – S = B – 10

As the distance between A and B is the same as the distance between B and A, the average speed is given by the formula =
=> => 3B2 – 300 = 80B.
=> 3B2 – 80B – 300 = 0 => 3B2 – 90B + 10B – 300 = 0
=> 3B(B – 30)+10(B – 30) = 0
=> (B-30)(3B+10) = 0
=> B = 30 or B = -10/3

As speed is a positive quantity, B = 30.

Therefore, D = 30 + 10 = 40 km/hr and U = 30 – 10 = 20 km/hr.

His onward journey was done at a speed of 40 km/hr. The distance covered was 60 kms.

Therefore, the time taken for the onward journey = = 1.5 hours
Question 4 the day: September 05, 2002
The question for the day is from the topic of Speed, Time and Distance.
A ship develops a leak 12 km from the shore. Despite the leak, the ship is able to move towards the shore at a speed of 8 km/hr. However, the ship can stay afloat only for 20 minutes. If a rescue vessel were to leave from the shore towards the ship, and it takes 4 minutes to evacuate the crew and passengers of the ship, what should be the minimum speed of the rescue vessel in order to be able to successfully rescue the people aboard the ship?
(1) 53 km/hr (2) 37 km/hr (3) 28 km/hr (4) 44 km/hr
Correct Answer – (2)

Solution:

The distance between the rescue vessel and the ship, which is 12 km has to be covered in 16 minutes. (The ship can stay afloat only 20 minutes and it takes 4 minutes to evacuate the people aboard the ship). Therefore, the two vessels should move towards each other at a speed of km/hr = = 45 km/hr.

The ship is moving at a speed of 8 km/hr. Therefore, the rescue vessel should move at a speed of 45 – 8 = 37 km/hr.
Question 4 the day: September 05, 2002
The question for the day is from the topic of Speed, Time and Distance.
A ship develops a leak 12 km from the shore. Despite the leak, the ship is able to move towards the shore at a speed of 8 km/hr. However, the ship can stay afloat only for 20 minutes. If a rescue vessel were to leave from the shore towards the ship, and it takes 4 minutes to evacuate the crew and passengers of the ship, what should be the minimum speed of the rescue vessel in order to be able to successfully rescue the people aboard the ship?
(1) 53 km/hr (2) 37 km/hr (3) 28 km/hr (4) 44 km/hr
Correct Answer – (2)

Solution:

The distance between the rescue vessel and the ship, which is 12 km has to be covered in 16 minutes. (The ship can stay afloat only 20 minutes and it takes 4 minutes to evacuate the people aboard the ship). Therefore, the two vessels should move towards each other at a speed of km/hr = = 45 km/hr.

The ship is moving at a speed of 8 km/hr. Therefore, the rescue vessel should move at a speed of 45 – 8 = 37 km/hr.
Question 4 the day: September 09, 2002
The question for the day is from the topic of Speed, Time and Distance.
A man driving his bike at 24 kmph reaches his office 5 minutes late. Had he driven 25% faster on an average he would have reached 4 minutes earlier than the scheduled time. How far is his office?
(1) 24 km (2) 72 km (3) 18 km (4) Data Insufficient
Correct Answer – (3)

Solution:

Let x km be the distance between his house and office.
While traveling at 24kmph, he would take hours. While traveling at 30 kmph, he would take hours. Therefore, (given in the problem. 5 min late + 4 min early = 9 min)
=> x = 18 km
Question 4 the day: September 23, 2002
The question for the day is from the topic of Speed, Time and Distance.
When an object is dropped, the number of feet N that it falls is given by the formula N = ½gt2 where t is the time in seconds from the time it was dropped and g is 32.2. If it takes 5 seconds for the object to reach the ground, how many feet does it fall during the last 2 seconds?
(1) 64.4 (2) 96.6 (3) 161.0 (4) 257.6
Correct Answer – (4)

Solution:

In 5 seconds it travels
½ * 32.2 * 52 = 16.1 * 25 = 402.5
In first 3 seconds it travels
½ * 32.2 * 32 = 16.1 * 9 = 144.9
Hence in the last 2 seconds it traveled 402.5 – 144.9 = 257.6
Question 4 the day: September 30, 2002
The question for the day is from the topic of Speed, Time and Distance.
If the wheel of a bicycle makes 560 revolutions in travelling 1.1 km, what is its radius?
(1) 31.25 cm (2) 37.75 cm (3) 35.15 cm (4) 11.25 cm
Correct Answer – (1)

Solution:

The distance covered by the wheel in 560 revolutions = 1100 m . Hence, the distance covered per revolution = metres. The distance covered in one revolution = circumference of the wheel.

Circumference = => r = 31.25 cm.
Question 4 the day: July 11, 2003

The question for the day is from the topic of Inequalities.
For what values of ‘x’ will the function be defined in the real domain?
(1) -10 0.

When x2 – 6x – 40 is 0.

Factorizing, we get (x – 10)(x + 4) > 0

This value of (x – 10)(x + 4) will be greater than or equal to 0 when both (x – 10) and (x + 4) are greater than or equal to 0 or when both (x – 10) and (x + 4) are less than or equal 0.

Case 1: When both (x – 10) and (x + 4) are greater than or equal to 0. X > 10 and x > – 4 => when x > 10 it will be greater than –4.

Therefore it will suffice to say that x > 10

Case 2: When both (x – 10) and (x + 4) are less than or equal to 0.

i.e. x when x

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