In what time will a railway train 120 m long moving at the rate of 36 kmph pass a telegraph post on its way?  Choose the correct answer:
A) 12 sec B) 7 sec C) 8 sec D) 9 sec E) 10 sec

Rationale: "t = 120 / 36 * 18 / 5 = 12 sec answer : a"
Answer: A