Question. A train 400 meters long completely crosses a 300 meters long bridge in 45 seconds. What is the speed of the train is?
Options:
(A) 32
(B) 56
(C) 29
(D) 27
(E) 21
Answer. (B)
What step-by-step reasoning justifies that answer?
Reasoning: S = (400 + 300)/45 = 700/45 * 18/5 = 56