A train passes a train standing in platform in 30 sec and a man standing on the platform in 12 sec. If the speed of the train is 36 km/hr. What is the length of the platform?
Choices:
A) 250  B) 200  C) 300  D) 240  E) 180
Speed = 36 * 5/18= 
<gadget id="calculator">36 * 5/18</gadget>
<output>10</output>
10 m/sec.   Length of the train= 10 * 12= 
<gadget id="calculator">10 * 12</gadget>
<output>120</output>
120 m.   Let the length of the platform be x m . Then,   (x + 120)/30= 10 =&gt; x = 180 m.   Answer: 180
<result>E</result>
A train passes a train standing in platform in 30 sec and a man standing on the platform in 12 sec. If the speed of the train is 36 km/hr. What is the length of the platform?