Question

Melissa walks 3 miles to the house of a friend and returns home on a bike. She averages 3 times faster when cycling than when walking,and the total time for both trips is two hours. Find her walking.

Answer 1

Given

Melissa walks 3 miles to the house of a friend and returns home on a bike. She averages 3 times faster when cycling than when walking,and the total time for both trips is two hours. Find her walking speed.

Solution

Total distance = 3miles

Let's represent speed with x

$\begin{gathered} \text{Walking time=}\frac{3}{x} \\ \text{cycling time=}\frac{3}{3x} \\ SINCE\text{ the total time is 2} \\ \frac{3}{x}+\frac{1}{x}=2 \\ \\ \frac{4}{x}=2 \\ 2x=4 \\ \text{divide both sides by 2} \\ \frac{2x}{2}=\frac{4}{2} \\ x=2mile\text{ per hour} \end{gathered}$

The final answer

$2\text{ mile per hour}$