A train 360 in long is running at a speed of 45 km/hour. In what time will it pass a bridge 140 m long?

A 40 sec

B 42 sec

C 45 sec

D 48 sec

Correct Answer: Option A

Convert 45km to m i.e. 45000m & 1hr=3600sec.

Then, 45000/3600sec. therefore 12.5m/sec. Total distance to be covered is 360m + 140m = 500m

Then, time required to pass the bridge is 500m/12.5m/s = 40sec.