Question

A girl goes to her friend’* house, which is at a distance of 12 km. she covers half of the distance at a speed of x km/hr. and the remaining distance at a speed of (x + 2) km/hr. If she takes 2 hrs 30 minutes to cover the whole distance, find ‘x’.

Answer 1

We know:

Time = Distance/Speed

Given, the girl covers a distance of 6 km at a speed x km/ hr.

Time taken to cover first 6 km = 6/x

Also, the girl covers the remaining 6 km distance at a speed (x + 2) km/ hr.

Time taken to cover next 6 km = 6/(x+2)

Total time taken to cover the whole distance = 2 hrs 30 mins

Since, speed cannot be negative. Therefore, x = 4.