Q: How long does a train 100 m long traveling at 72 kmph takes to cross a tunnel of 1400 m in length?
Options:
(A) 70 sec
(B) 60sec
(C) 82 sec
(D) 75 sec
(E) 62 sec Let's give some random thoughts before answering.
D = 1400+100 = 1500 m
S = 72 * 5/18 = 20
T = 1500 * 1/20 = 75 sec
Therefore, the answer is (D).