A train passes a station platform in 48 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?	Select the correct option
A) 476 m  B) 420 m  C) 440 m  D) 407 m  E) 402 m
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 meters.   Then, x + 300 / 48= 15   x + 300 = 720   x =420 m.   Answer: 420 m
<result>B</result>
A train passes a station platform in 48 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?