The time taken by a person to cover 150 km was hours more than the speed while going, find the speed per hour in each direction.

Let us assume the speed of person while going = x km/hr

Also, speed of a person while returning = (x + 10) km/hr

It is given in the question that,

Total distance covered by person = 150 km

We know that,

x (x + 10) = 600

x² + 10x – 600 = 0

_x² + 30x – 20x – 600 = 0

_{(x + 30) (x – 20) = 0}

_{∴ x + 30 = 0 or x – 20 = 0}

_{x = - 30 or x = 20}

As the speed of covering the distance cannot be negative therefore, x = 20 km/hr

Hence, speed while going = x = 20 km/hr

And, speed while returning = (x + 10)

= 20 + 10 = 30 km/hr