In what time will a railway train 70 m long moving at the rate of 36 kmph pass a telegraph post on its way?	Choose the correct option:
A) 6 sec  B) 7 sec  C) 8 sec  D) 9 sec  E) 2 sec

Rationale: "t = 70 / 36 * 18 / 5 = 7 sec answer : b"
Answer: B