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:

Answer 1

Hey!

Given,
Distance = 125 m
Speed = 5 km/hr
Time = 10 s

We know,
Speed of train relative to man = Distance/time
                                                = 125/10
                                               = 25/2 m/s
                                               = 25/2 * 8/15 km/hr
                                               = 45 km/hr
Now, 
let speed of train be s,
Relative speed = x - 5
hence, x-5 = 54
            x = 50 km/hr

hence, speed of train is 50 km/hr.

Answer 2

Heya,

Answer to your question is:-

Speed of the train relative to man = Distance/Time
=125/10 = 25/2 m/s
=[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.

So,x-5= 45

=> x = 50 km/hr.

Therefore, the speed of the train is 50 km/hr.ANSWER....

HOPE THIS HELPS YOU:-))
@Ashu