Two trains are running at 40 km/hr and 20 km/hr 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) 27 (7/9)m  D) 29 m  E) 28 m
Relative speed = (40 - 20) km/hr =	(20 x(5/18))m/sec =	(50/9)m/sec.   Therefore Length of faster train =	((50/9)	x 4) m =	(200/9)m = 22	(2/9)	m.   22 (2/9)m
<result>B</result>
Two trains are running at 40 km/hr and 20 km/hr 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?