A train 825 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 90 seconds. The speed of the train is:
Choose the correct choice from the following answers:	A) 33	B) 27	C) 27	D) 50	E) 81
Speed of the train relative to man = (125/10) m/sec = (25/2) m/sec. [(25/2) * (18/5)] km/hr = 45 km/hr. Let the speed of the train be x km/hr. Then, relative speed = (x - 5) km/hr. x - 5 = 45 ==&gt; x = 50 km/hr.   Answer:50
<result>D</result>
A train 825 m long passes a man, running at 5 km/hr in the same direction in which the train is going, in 90 seconds. The speed of the train is: