Question: A pipe can fill a cistern in 20 minutes whereas the cistern when fill can be emptied by a leak in 30 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17 minutes
(B) 87 minutes
(C) 60 minutes
(D) 27 minutes
(E) 11 minutes
Answer: 1/20 - 1/30 = 1/60
60 minutes
The answer is (C).

Question: How many positive integers less than 70 have a reminder 01 when divided by 3?
Options:
(A) 13
(B) 24
(C) 35
(D) 16
(E) 17
Answer: 1 also gives the remainder of 1 when divided by 3. So, there are total of 24 numbers.
The answer is (B).

Question: A man purchased 3 blankets @ Rs.100 each, 5 blankets @ Rs.150 each and two blankets at a certain rate which is now slipped off from his memory. But he remembers that the average price of the blankets was Rs.162. Find the unknown rate of two blankets?
Options:
(A) 420
(B) 550
(C) 490
(D) 570
(E) 457
Answer: 10 * 162 = 1620
3 * 100 + 5 * 150 = 1050
1620 1050 = 570
The answer is (D).

Question: n what time will a railway train 60 m long moving at the rate of 36 kmph pass a telegraph post on its way?
Options:
(A) 2
(B) 7
(C) 8
(D) 6
(E) 9
Answer:
T = 60/36 * 18/5 = 6 sec
The answer is (D).