A train passes a train standing in platform in 30 sec and a man standing on the platform in 12 sec. If the speed of the train is 36 km/hr. What is the length of the platform? Choose the correct choice from the following options:
A) 250 B) 200 C) 300 D) 240 E) 180

Rationale: speed = 36 * 5 / 18 = 10 m / sec . length of the train = 10 * 12 = 120 m . let the length of the platform be x m . then , ( x + 120 ) / 30 = 10 = > x = 180 m . answer : e
Answer: E