A train 125 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 answer:
A) 50 km/hr B) 15 km/hr C) 6 km/hr D) 8 km/hr E) 12 km/hr
Explanation:   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.   50 km/hrnswer: 50 km/hr) 50 km/hr.
<result>A</result>
A train 125 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: