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
r speed of the train relative tio man = 125/10 m/sec.
= 25/2 m/sec
= (25/2)X(18/5) km/hr
= 45 km/hr