Rationale: Work done by X in 1 day = 1/21
Work done by Y in 1 day = 1/15
Work done by Y in 5 days = 5/15 = 1/3
Remaining work = 1 1/3 = 2/3
Number of days in which X can finish the remaining work = (2/3) / (1/21) = 14
The answer: (D)
Question: X can finish a work in 21 days. Y can finish the same work in 15 days. Y worked for 5 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 12
(B) 13
(C) 16
(D) 14
(E) 18
Reasoning: P = (P*7*R)/100
R = 14 2/7%
Ans: (C)
Question: In what time a sum of money double itself at 7% per annum simple interest?
Options:
(A) 33 1/8%
(B) 33 1/3%
(C) 14 2/7%
(D) 32 1/3%
(E) 23 1/3%
Rationale: 10 books can be rearranged in 10! ways consider the two books taken as a pair then number of favourable ways of getting these two books together is 9! 2!
Required probability = 1/5
The answer: (C)
Question: 10 books are placed at random in a shelf. The probability that a pair of books will always be together is ?
Options:
(A) 1/8
(B) 1/2
(C) 1/5
(D) 1/5
(E) 1/3
Reasoning: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 15 = 250 m
Ans: (D)
Question: A train running at the speed of 60 km/hr crosses a pole in 15 sec. What is the length of the train?
Options:
(A) 118
(B) 150
(C) 277
(D) 250
(E) 191
Rationale: The sum all three digits comes to 10 except 324
The answer: (A)
Question: Find the odd man out
253, 136, 352, 324, 631, 244
Options:
(A) 324
(B) 136
(C) 352
(D) 631
(E) 531
Rationale: Given Exp. = (12)3 x 64 = (12)3 x 64 = (12)2 x 62 = (72)2 = 5184
432 12 x 62
The answer: (E)
Question: Find the value of y from (12)^3 x 6^4 432 = y?
Options:
(A) 1234
(B) 2343
(C) 4546
(D) 3435
(E) 5184