A 180m long train is running at 72 kmph.If it crossed the platform in 20 sec.then find the platform length?	Choose the correct choice from the following answers
A) 220m B) 110m C) 230m D) 100m E) 90m
Length=speed*time   Length=72km/hr*time   Length=[72*(5/18)]*20 {(ie)(x)km/hr)}   =x*(5/18)   =20*20= 
<gadget id="calculator">20*20</gadget>
<output>400</output>
400m   Length of platform=Length-Length of the train   Length of platform=400-180= 
<gadget id="calculator">400-180</gadget>
<output>220</output>
220m   Option 220m
<result>A</result>
A 180m long train is running at 72 kmph.If it crossed the platform in 20 sec.then find the platform length?