A train 105 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is:	Choose the correct choice from the following answers.
A) 22  B) 50  C) 42.8  D) 288  E) 12
Speed of the train relative to man = (105/10) m/sec = (21/2) m/sec. [(21/2) * (18/5)] km/hr = 37.8 km/hr. Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr. x - 5 = 37.8 ==&gt; x = 42.8 km/hr.Answer: 42.8
<result>C</result>
A train 105 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 10 seconds. The speed of the train is: