Question: A train running at the speed of 60 km/hr crosses a pole in 18 sec. What is the length of the train?
Options:
(A) 118
(B) 150
(C) 300
(D) 258
(E) 191
Answer: Speed = 60 * 5/18 = 50/3 m/sec
Length of the train = speed * time = 50/3 * 18 = 300 m
The answer is (C).

Question: For integers U and V, when U is divided by V, the remainder is odd. Which of the following must be true?
Options:
(A) At least one of U and V is odd
(B) The sum U + V is odd
(C) U and V share no common factors other than 1
(D) UV is odd.
(E) U is odd
Answer: At least one of U and V is odd
The answer is (A).

Question: A pipe can fill a cistern in 7 minutes whereas the cistern when fill can be emptied by a leak in 14 minutes. When both pipes are opened, find when the cistern will be full?
Options:
(A) 17
(B) 16
(C) 70
(D) 14
(E) 12
Answer: 1/7 - 1/14 = 1/14
14 minutes
The answer is (D).

Question: If 1/2 of the air in a tank is removed with each stroke of a vacuum pump, what fraction of the original amount of air has been removed after 1 strokes ?
Options:
(A) 1/2
(B) 7/8
(C) 1/4
(D) 1/8
(E) 1/16
Answer:
Left After 1st stroke = 1/2
So removed = 1- 1/2 = 1/2
The answer is (A).