A man is standing on a railway bridge which is 240 m long. He finds that a train crosses the bridge in 20 seconds but himself in 8 seconds. Find the length of the train and its speed.
Choose the correct answer:
A) 10 m/sec
B) 15 m/sec
C) 18 m/sec
D) 20 m/sec
E) 25 m/sec
If length of train is l and speed of train is s, then   l/s = 8   (l+240)/s = 20   (l+240)/l = 20/8 =5/2   2l+480 =5*l   3*l= 480   l=160 mtrs   s= l/8 = 160/8= 
<gadget id="calculator">160/8</gadget>
<output>20</output>
20 m/sec   ANSWER:20 m/sec
<result>D</result>
A man is standing on a railway bridge which is 240 m long. He finds that a train crosses the bridge in 20 seconds but himself in 8 seconds. Find the length of the train and its speed.