A train passes a platform in 22 seconds. The same train passes a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, The length of the platform is	Pick: A) 40 B) 50 C) 60 D) 30 E) 20
Speed of the train = 54 km/hr = (54×10)/36 m/s = 15 m/s   Length of the train = speed × time taken to cross the man = 15×20 = 300 m   Let the length of the platform = L   Time taken to cross the platform = (300+L)/15   =&gt; (300+L)/15 = 12   =&gt; 300+L = 15×22 = 330   =&gt; L =330-300= 
<gadget id="calculator">330-300</gadget>
<output>30</output>
30 meter   Answer is 30.
<result>D</result>
A train passes a platform in 22 seconds. The same train passes a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, The length of the platform is