Question

A passenger train takes 3 hours less for a journey of 360 km, if its speed is increased by 10 km/hr from its usual speed. What is the usual speed?

Answer 1

Let the usual speed of train bethen,

Increased speed of the train

Time taken by the train under usual speed to cover

Time taken by the train under increased speed to cover

Therefore,

So, either

Or

But, the speed of the train can never be negative.

Hence, the usual speed of train is