The length of the bridge, which a train 120 metres long and travelling at 45 km/hr can cross in 30 seconds, is:
Pick one:
A) 230
B) 240
C) 245
D) 255
E) 260
Speed = [45 X 5/18] m/sec = [25/2] m/sec Time = 30 sec Let the length of bridge be x metres. Then, (120 + x)/30 = 25/2 =&gt; 2(120 + x) = 750 =&gt; x = 255 m.   Answer: Option 255
<result>D</result>
The length of the bridge, which a train 120 metres long and travelling at 45 km/hr can cross in 30 seconds, is: