A train passes a station platform in 35 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? Choose the correct choice from the following choices.
A) 248 m  B) 225 m  C) 277 m  D) 765 m  E) 176 m
Speed = (54 * 5/18) m/sec = 15 m/sec. Length of the train = (15 x 20)m = 300 m. Let the length of the platform be x meters. Then, (x + 300)/35 = 15 ==&gt; x + 300 = 525 ==&gt; x   = 225 m.   Answer: 225 m
<result>B</result>
A train passes a station platform in 35 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?