Reasoning: Work done by X in 1 day = 1/21
Work done by Y in 1 day = 1/15
Work done by Y in 10 days = 10/15 = 2/3
Remaining work = 1 2/3 = 1/3
Number of days in which X can finish the remaining work = (1/3) / (1/21) = 7
Ans: (C)
Question: X can finish a work in 21 days. Y can finish the same work in 15 days. Yworked for 10 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 3
(B) 5
(C) 7
(D) 8
(E) 9
Rationale: T = 128/32 = 4 h
T = 4 - 3 = 1
Time Ratio = 4:1 = 4:1
Speed Ratio = 1:4
The answer: (C)
Question: A motorcyclist goes from Bombay to Pune, a distance of 128 kms at an average of 32 kmph speed. Another man starts from Bombay by car 2 hours after the first, and reaches Pune hour earlier. What is the ratio of the speed of the motorcycle and the car?
Options:
(A) 1:3
(B) 1:5
(C) 1:4
(D) 1:1
(E) 1:8
Reasoning: According to the information in the question the maximum range would be between 400 and 700(300). The minimum range would be the greatest range for any one individual, which is listed in the problem as 100. So the difference between these would be 300-100 or 200.
Ans: (E)
Question: Three people took GMAT practice tests in which the minimum and maximum possible scores are 200 and 800, respectively. They each took a test 3 times, and no one scored below 400 or over 700. If the individual ranges of the three people's scores in those 3 practice tests were 40, 70 and 100, what is the difference between the maximum and minimum possible ranges of all their scores put together.
Options:
(A) 70
(B) 80
(C) 100
(D) 140
(E) 200
Rationale: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 12 = 200 m
The answer: (B)
Question: A train running at the speed of 60 km/hr crosses a pole in 12 sec. What is the length of the train?
Options:
(A) 356
(B) 200
(C) 127
(D) 279
(E) 150
Reasoning: 20000(11/10)4 - 20000(6/5)2 = 482
Ans: (A)
Question: How much more would Rs.20000 fetch, after two years, if it is put at 20% p.a. compound interest payable half yearly than if is put at 20% p.a. compound interest payable yearly?
Options:
(A) 482
(B) 725
(C) 992
(D) 837
(E) 923
Reasoning: Number of ways = 61/21 6X5X4X3X2X1 - 360
Ans: (E)
Question: In how many different ways can the letters of the word 'PREPTY' be arranged?
Options:
(A) 280
(B) 290
(C) 300
(D) 340
(E) 360