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 4 seconds.What is the length of the fast train? Choices:
A) 23 m  B) 22 2/9 m  C) 27m  D) 27 7/9m  E) 29 7/9m
relative speed=20kmph=50/9m/sec   length of the train=50/9*4= 22 2/9m   ANSWER:22 2/9 m
<result>B</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 4 seconds.What is the length of the fast train?