Reasoning: Speed downstream = d/t = 120/(4) = 30 kmph
Speed upstream = d/t = 92/(4) = 23 kmph
The speed of the stream = (30 - 23)/2 = 4 kmph
Ans: (B)
Question: A man rows his boat 120 km downstream and 92 km upstream, taking 4 hours each time. Find the speed of the stream?
Options:
(A) 6 kmph
(B) 4 kmph
(C) 2 kmph
(D) 8 kmph
(E) 1 kmph

Reasoning: Work done by X in 1 day = 1/20
Work done by Y in 1 day = 1/16
Work done by Y in 12 days = 12/16 = 3/4
Remaining work = 1 3/4 = 1/4
Number of days in which X can finish the remaining work = (1/4) / (1/20) = 5
Ans: (D)
Question: X can finish a work in 20 days. Y can finish the same work in 16 days. Y worked for 12 days and left the job. how many days does X alone need to finish the remaining work?
Options:
(A) 2
(B) 3
(C) 9
(D) 5
(E) 8

Reasoning: 560 = 2*2*2*2*7*5
Required smallest number = 7 * 5 = 35
35 is the smallest number which should be multiplied with 560 to make it a perfect squar
Ans: (E)
Question: Find the smallest number which should be multiplied with 560 to make it a perfect square.
Options:
(A) 60
(B) 55
(C) 45
(D) 25
(E) 35

Reasoning: 3872 = 11*11*2*2*2*2*2
Required smallest number = 2
2 is the smallest number which should be divided with 3872 to make it a perfect square.
Ans: (C)
Question: Find the smallest number which should be divided with 3872 to make it a perfect square.
Options:
(A) 8
(B) 6
(C) 2
(D) 4
(E) 1