q: A train 200 meters long completely crosses a 300 meters long bridge in 45 seconds. What is the speed of the train is?
Options:
(A) 10
(B) 20
(C) 30
(D) 40
(E) 50
a: OK... S = (200 + 300)/45 = 500/45 * 18/5 = 40
The answer is (D).

q: A train of 24 carriages, each of 60 meters length, when an engine also of 60 meters length is running at a speed of 60 kmph. In what time will the train cross a bridge 1.4 km long?
Options:
(A) 2 mins 14 sec
(B) 2 mins 34 sec
(C) 2 mins 54 sec
(D) 4 mins 54 sec
(E) 2 mins 44 sec
a: OK... D = 25 * 60 + 1400 = 2900 m
T = 2900/60 * 18/5 = 174 sec = 2 mins 54 se
The answer is (C).

q: A train 250 m long running at 72 kmph crosses a platform in 40 sec. What is the length of the platform?
Options:
(A) 450m
(B) 200m
(C) 250m
(D) 270m
(E) 300 m
a:
OK... D = 72 * 5/18 = 40 = 800 â€“ 250 = 450m
The answer is (A).