How long does a train 60 m long travelling at 60 kmph takes to cross a bridge of 80 m in length?	Pick one:
A) 5.8 sec
B) 8.4 sec
C) 12.4 sec
D) 6.8 sec
E) 1.8 sec

Rationale: "b 16.8 sec d = 60 + 80 = 140 m s = 60 * 5 / 18 = 50 / 3 t = 140 * 3 / 50 = 8.4 sec answer is b"
Answer: B