Question: A man rows his boat 84 km downstream and 48 km upstream, taking 2 hours each time. Find the speed of the stream?
Options:
(A) 6 kmph
(B) 5 kmph
(C) 9 kmph
(D) 8 kmph
(E) 1 kmph
Answer: Speed downstream = d/t = 84/(2) = 42 kmph
Speed upstream = d/t = 48/(2) = 24 kmph
The speed of the stream = (42 - 24)/2 = 9 kmph
The answer is (C).

Question: 10 men and 15 women together can complete a work in 4 days. It takes 100 days for one man alone to complete the same work. How many days will be required for one woman alone to complete the same work?
Options:
(A) 100 days
(B) 667 days
(C) 177 days
(D) 187 days
(E) 225 days
Answer: 1 man's 1 day work = 1/100
(10 men + 15 women)'s 1 day work = 1/4
15 women's 1 day work = (1/4 - 10/100) = 3/20
1 woman's 1 day work = 1/100
1 woman alone can complete the work in 100 days.
The answer is (A).

Question: At what rate percent on simple interest will a sum of money double itself in 30 years?
Options:
(A) 3 1/3%
(B) 3 1/7%
(C) 3 9/3%
(D) 3 5/3%
(E) 3 3/3%
Answer: P = (P*30*R)/100
R = 3 1/3%
The answer is (A).

Question: In a school of 650 boys, 44% of Muslims, 28% Hindus, 10% Sikhs and the remaining of other communities. How many belonged to the other communities?
Options:
(A) 173
(B) 163
(C) 153
(D) 143
(E) 117
Answer:
44 + 28 + 10 = 82%
100 82 = 18%
650 * 18/100 = 117
The answer is (E).