Let the actual speed of the train be x Km/hr and the actual time taken by y hours. Then,
Distance covered= speed×time
If the speed is increased by, then time of journey is reduced by 1 hour i.e., when speed is , time of journey is
Distance covered= km
xy=(x+12)(y−1)
...(ii)
When the speed is reduced by, then the time of journey is increased by i.e., when speed is, time of journey is
Distance covered =
Thus we obtain the following equations
By using elimination method, we have
Putting the value in equation (iii) we get
Putting the value of x and y in equations (i) we get
Distance covered =
=
Hence, the distance is,
The speed of walking is .