q: A 180 meter long train crosses a man standing on the platform in 9 sec. What is the speed of the train?
Options:
(A) 72
(B) 108
(C) 1266
(D) 188
(E) 211
a: OK... S = 180/9 * 18/5 = 72 kmph
The answer is (A).

q: The no. of girls in a class are 7times the no. of boys, which value cannever be the of total students?
Options:
(A) 20
(B) 35
(C) 30
(D) 40
(E) 42
a: OK... Let the boys are X, then girls are 7X, total = X+7X = 8X
So it should be multiple of 8, 30 is not a multiple of 8.
The answer is (C).

q: How long does a train 110 m long traveling at 60 kmph takes to cross a bridge of 140 m in length?
Options:
(A) 16.5
(B) 16.0
(C) 15
(D) 16.8
(E) 16.1
a:
OK... D = 110 + 140 = 250 m
S = 60 * 5/18 = 50/3
T = 250 * 3/50 = 15 se
The answer is (C).