A train running at a speed of 36 km/h passes an electric pole in 15 seconds. In how many seconds will the whole train pass a 380-meter long platform?
Choose the correct choice.
A) 47  B) 49  C) 51  D) 53  E) 55

Rationale: "let the length of the train be x meters . when a train crosses an electric pole , the distance covered is its own length x . speed = 36 km / h = 36000 m / 3600 s = 10 m / s x = 15 * 10 = 150 m . the time taken to pass the platform = ( 150 + 380 ) / 10 = 53 seconds the answer is d ."
Answer: D