Two trains are running at 40km/hr and 20km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast train?	Choose the correct choice from the following:	A) 23 m	B) 23 2/9 m	C) 27 7/9 m	D) 29 m	E) 28 m
SOLUTION:   Relative speed =(40-20)km/hr=(20*5/18)m/sec=(50/9)m/sec.   Therefore length of faster train = ((50/9)*5)m=250/9 m = 27 7/9 m.   Answer: 27 7/9 m
<result>C</result>
Two trains are running at 40km/hr and 20km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast train?