A train running at a speed of 36 kmph crosses an electric pole in 12 seconds. In how much time will it cross a 340 m long platform?  Choose the correct option:
A) 19  B) 27  C) 29  D) 46  E) 28

Rationale: "let the length of the train be x m . when a train crosses an electric pole , the distance covered is its own length . so , x = 12 * 36 * 5 / 18 m = 120 m . time taken to cross the platform = ( 120 + 340 ) / 36 * 5 / 18 = 46 min . answer : d"
Answer: D