How long does a train 150 m long traveling at 36 kmph takes to cross a signal post? Choose the correct choice:  A) 8 sec  B) 15 sec  C) 20 sec  D) 10 sec  E) 22 sec

Rationale: d = 150 m s = 36 * 5 / 18 = 10 t = 150 * 1 / 10 = 15 sec answer : b
Answer: B