Question: In what time a sum of money double itself at 6% per annum simple interest?
Options:
(A) 33 1/8%
(B) 16 2/3%
(C) 33 7/3%
(D) 32 1/3%
(E) 23 1/3%
Answer: P = (P*6*R)/100
R = 16 2/3%
The answer is (B).

Question: A 160 meter long train crosses a man standing on the platform in 18 sec. What is the speed of the train?
Options:
(A) 96 kmph
(B) 94 kmph
(C) 32 kmph
(D) 56 kmph
(E) 76 kmph
Answer: S = 160/18 * 18/5 = 32 kmph
The answer is (C).

Question: John makes $40 a week from his job. He earns a raise andnow makes $70 a week. What is the % increase?
Options:
(A) 16%
(B) 16.66%
(C) 76.69%
(D) 76.98%
(E) 75%
Answer: Increase = (30/40)*100 = (3/4)*100 = 75%.
The answer is (E).

Question: Three pipes A, B and C can fill a tank from empty to full in 30 minutes, 20 minutes and 10 minutes respectively. When the tank is empty, all the three pipes are opened. A, B and C discharge chemical solutions P, Q and R respectively. What is the proportion of solution R in the liquid in the tank after 3 minutes?
Options:
(A) 6/18
(B) 6/11
(C) 6/68
(D) 6/19
(E) 6/12
Answer:
Part filled by (A + B + C) in 3 minutes = 3(1/30 + 1/20 + 1/10) = 11/20
Part filled by C in 3 minutes = 3/10
Required ratio = 3/10 * 20/11 = 6/11
The answer is (B).