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:

Question: 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:
[A].

45 km/hr

[B].

50 km/hr

[C].

54 km/hr

[D].

55 km/hr

Answer: Option B

Explanation:

Speed of the train relative to man =		125	m/sec
		10

=		25	m/sec.
		2

=		25	x	18	km/hr
		2		5

   = 45 km/hr.

Let the speed of the train be x km/hr. Then, relative speed = (x – 5) km/hr.

x – 5 = 45         x = 50 km/hr.