arithmetic - a train 250 m long passes a man running at 10 kmhr in the same direction in which the train is going in 10 sec the speed of the train is - skillgun

Speed of the train relative to man = (250/10) m/sec = 25 m/sec.
= (25 * 18/5) km/hr
= 90 km/hr
Let the speed of the train be x km/hr. then, relative speed
= (x - 10) km/hr.
.'. x - 10 = 90
or x = 80 km/hr.