The length of the bridge, which a train 100 metres long and travelling at 45 km/hr can cross in 30 seconds, is?
Choices.
A) 10 m  B) 16 m  C) 275 m  D) 19 m  E) 27 m
Speed = [45 X 5/18] m/sec = [25/2] m/sec Time = 30 sec Let the length of bridge be x metres. Then, (100 + x)/30   = 25/2 =&gt; 2(100 + x) = 750 =&gt; x   = 275 m.   Answer: 275 m
<result>C</result>
The length of the bridge, which a train 100 metres long and travelling at 45 km/hr can cross in 30 seconds, is?