A train passes a bridge in 40 sec and a man standing on the platform in 20 sec. If the speed of the train is 54 km/hr. What is the length of the platform?
Choose one
A) 250 B) 400 C) 150 D) 300 E) 450
Speed = 54 * 5/18= 
<gadget id="calculator">54 * 5/18</gadget>
<output>15</output>
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 m . Then,   (x + 300)/40= 15 =&gt; x = 300 m.   Answer: 300
<result>D</result>
A train passes a bridge in 40 sec and a man standing on the platform in 20 sec. If the speed of the train is 54 km/hr. What is the length of the platform?