A train passes a station platform in 36 sec and a man standing on the platform in 20 sec. If the speed of the train is 108 km/hr. What is the length of the platform?	Choose the correct choice from the following choices.
A) 229
B) 240
C) 288
D) 480
E) 221
Speed = 108 * 5/18= 
<gadget id="calculator">108 * 5/18</gadget>
<output>30</output>
30 m/sec.   Length of the train= 30 * 20= 
<gadget id="calculator">30 * 20</gadget>
<output>600</output>
600 m.   Let the length of the platform be x m . Then,   (x + 600)/36= 30 =&gt; x = 480 m.   Answer: 480
<result>D</result>
A train passes a station platform in 36 sec and a man standing on the platform in 20 sec. If the speed of the train is 108 km/hr. What is the length of the platform?