A man sitting in a train which is traveling at 50 kmph observes that a goods train, traveling in opposite direction, takes 9 seconds to pass him. If the goods train is 150 m long, find its speed.	Choose the correct option:  A) 20 km/hr  B) 10 km/hr  C) 15 km/hr  D) 18 km/hr  E) 19 km/hr
speed of train = 50 kmph = 50*5/18 = 250/18 m/sec   relative speed =(250/18)+x where x is speed of goods train   then   150/((250/18)+x) = 9   solving it, we get   x= 50/18 m/sec = 10 km/hr   ANSWER:10 km/hr
<result>B</result>
A man sitting in a train which is traveling at 50 kmph observes that a goods train, traveling in opposite direction, takes 9 seconds to pass him. If the goods train is 150 m long, find its speed.