Chapter 7, Problem 6PTTS

To determine

To calculate: The number of hours per week spent walking from home to school and back home.

Answer to Problem 6PTTS

  $2\frac{1}{3}\text{ hours per week}$ is spent on walking from home to school and back home.

Explanation of Solution

Given information:

Number of days = $5$

Time taken to walk from home to school or school to home = $14\text{ minutes}$

Calculation:

To find the time taken per week, use equivalent rate.

The time spent each day to travel from home to school and back home = $14+14=28\text{ minutes}$

Therefore, time taken per day can be expressed as:

  $\frac{28\text{ min}}{1\text{ day}}$

Express this rate in minutes per week(taking $5$ days a week)

  $\begin{array}{l}\frac{28\text{ min}}{1\text{ day}}\\ \Rightarrow \frac{28\text{ min}}{1\cancel{\text{day}}}\times \frac{\text{5 }\cancel{\text{days}}}{1\text{ week}}\text{ [Multiply by conversion factor and divide out common factors and units]}\\ \Rightarrow \frac{140\text{ minutes}}{1\text{ week}}\text{ [Simplify]}\end{array}$

Now express

  $\frac{140\text{ minutes}}{1\text{ week}}$ in hours per week.

  $\begin{array}{l}\frac{140\text{ minutes}}{1\text{ week}}\\ \Rightarrow \frac{\cancel{\stackrel{7}{\text{140}}}\cancel{\text{min}}}{1\text{ week}}\times \frac{\text{1 hour}}{\cancel{\underset{3}{\text{60}}}\cancel{\text{min}}}\text{ [Multiply by conversion factor and divide out common factors and units]}\\ \Rightarrow \frac{7/3\text{ hours}}{1\text{ week}}\text{ [Simplify]}\\ \Rightarrow 2\frac{1}{3}\text{ hours per week [Write as mixed fraction]}\end{array}$

Therefore,

  $2\frac{1}{3}\text{ hours per week}$ is spent on walking.