Two trains are running at 40 kmph and 20 kmph respectively in the same direction.Fast train completely passes a man sitting in the slower train in 9 seconds.What is the length of the fast train?	Choose one:
A) 23 m B) 23 2/9 m C) 27m D) 46 m E) 50 m
relative speed=20kmph=50/9m/sec   length of the train=50/9*9= 
<gadget id="calculator">50/9*9</gadget>
<output>50</output>
50 m   ANSW50 mR:50 m
<result>E</result>
Two trains are running at 40 kmph and 20 kmph respectively in the same direction.Fast train completely passes a man sitting in the slower train in 9 seconds.What is the length of the fast train?