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

Answer:

a) $t_{1} = \frac{8}{x}\,h$, b) $t_{2} = \frac{7.5}{x}\,h$, c) $v=6\,\frac{km}{h}$

Step-by-step explanation:

a) The time taken is:

$t_{1} = \frac{8\,km}{x}$

$t_{1} = \frac{8}{x}\,h$

b) The time taken is:

$t_{2} = \frac{15\,km}{2\cdot x}$

$t_{2} = \frac{7.5}{x}\,h$

c) The walking speed of the student is:

$2.583\,h = \frac{8\,km}{v} + \frac{15\,km}{2\cdot v}$

$2.583\,h = \frac{31\,km}{2\cdot v}$

$v = 6\,\frac{km}{h}$