Question

A student walks 8 km at x km/h. He then cycles 15 km at 2x km/h. In terms of x write down the time taken in hours a)when walking b)when cycling c)if the total time for the journey is 2 h 35 min, find the student's walking speed.

Answer 1

a)
`t_(1) = (8)/(x)\,h`, b)
`t_(2) = (7.5)/(x)\,h`, c)
`v=6\,(km)/(h)`

Explanation:

a) The time taken is:

`t_(1) = (8\,km)/(x)`

`t_(1) = (8)/(x)\,h`

b) The time taken is:

`t_(2) = (15\,km)/(2\cdot x)`

`t_(2) = (7.5)/(x)\,h`

c) The walking speed of the student is:

`2.583\,h = (8\,km)/(v) + (15\,km)/(2\cdot v)`

`2.583\,h = (31\,km)/(2\cdot v)`

`v = 6\,(km)/(h)`