How many seconds will a train 100 meters long take to cross a bridge 150 meters long if the speed of the train is 42 kmph?	Choose the correct choice from the following choices
A) 21.4 sec B) 77 sec C) 25 sec D) 18 sec E) 17 sec

Rationale: "d = 100 + 150 = 250 s = 42 * 5 / 18 = 11.7 mps t = 250 / 11.7 = 21.4 sec answer : a"
Answer: A