A train is 485 meter long is running at a speed of 45 km/hour. In what time will it pass a bridge of 140 meter length	Choose the correct choice.
A) 20 seconds  B) 30 seconds  C) 40 seconds  D) 50 seconds  E) none of these

Rationale: "explanation : speed = 45 km / hr = 45 * ( 5 / 18 ) m / sec = 25 / 2 m / sec total distance = 485 + 140 = 625 meter time = distance / speed = 625 ∗ 2 / 25 = 50 seconds option d"
Answer: D