A train passes a station platform in 20 sec and a man standing on the platform in 12 sec. If the speed of the train is 72 km/hr. What is the length of the platform?  Choose the correct answer.
A) 227 B) 140 C) 160 D) 120 E) 171
Speed = 72 * 5/18= 
<gadget id="calculator">72 * 5/18</gadget>
<output>20</output>
20 m/sec.   Length of the train= 20* 12= 
<gadget id="calculator">20* 12</gadget>
<output>240</output>
240 m.   Let the length of the platform be x m . Then,   (x + 240)/20= 20=&gt; x = 160 m.   Answer:160
<result>C</result>
A train passes a station platform in 20 sec and a man standing on the platform in 12 sec. If the speed of the train is 72 km/hr. What is the length of the platform?