A train passes a station platform in 42 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?	Pick:
A) 180 m	B) 240 m	C) 330 m	D) 280 m	E) 380 m
Speed = 54 x 5/18 = 15 m/s   Length of the train = (15 x 20)m = 300 m.   Let the length of the platform be x metres.   Then, (x + 300)/42 = 15   --&gt; x + 300 = 630   x = 330m.   Answer : 330 m.
<result>C</result>
A train passes a station platform in 42 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?