A train passes a station platform in 38 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?  Options:  A) 180 m  B) 200 m  C) 270 m  D) 320 m  E) None
Sol.   Speed = [54 * 5/18] m/sec = 15 m/sec.   Length of the train = (15 * 20)= 
<gadget id="calculator">(15 * 20)</gadget>
<output>300</output>
300 m.   Let the length of the platform be x metres.   Then, x + 300 / 38= 15 ⇔ x + 300 = 570 ⇔ x = 270 m.   Answer 270 m
<result>C</result>
A train passes a station platform in 38 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?