How many seconds will a 400 m long train take to cross a man walking with a speed of 3 km/hr in the direction of the moving train if the speed of the train is 63 km/hr?	Choose one.
A) 20 B) 30 C) 40 D) 24 E) 60

Rationale: "speed of train relative to man = 63 - 3 = 60 km / hr . = 60 * 5 / 18 = 50 / 3 m / sec . time taken to pass the man = 400 * 3 / 50 = 24 sec . answer : option d"
Answer: D