A train 400 m long can cross an electric pole in 20 sec and then find the speed of the train?  Choose the correct choice.
A) 72	B) 70	C) 60	D) 85	E) 90
Length = speed*time   S=400/20= 
<gadget id="calculator">400/20</gadget>
<output>20</output>
20 m/sec   Speed= 20*18/5= 
<gadget id="calculator">20*18/5</gadget>
<output>72</output>
72 kmph   72NSWER 72
<result>A</result>
A train 400 m long can cross an electric pole in 20 sec and then find the speed of the train?