Chapter 11.6, Problem 49PPS

(a)

To determine

To write: an expression to represent the amount of time

Answer to Problem 49PPS

The simplified expression is $\frac{7}{2.5w}$

Explanation of Solution

Given:

G walks $2miles$ away.

Walking speed of G is $w$ .

Jogging speed is $2.5$ times her walking speed $w$ .

Calculation:

The expression is as follows.

  $\frac{2}{w}+\frac{2}{2.5w}$

The expression is simplified below.

  $\begin{array}{l}\frac{2}{w}+\frac{2}{2.5w}\\ =\frac{2}{w}\left(\frac{2.5}{2.5}\right)+\frac{2}{2.5w}\\ =\frac{5+2}{2.5w}\\ =\frac{7}{2.5w}\end{array}$

Conclusion:

The simplified expression is $\frac{7}{2.5w}$

(b)

To determine

To find: the time spends to go and return back from her friend’s house

Answer to Problem 49PPS

The time spends to go and return back from her friend’s house is $48\text{ min}$

Explanation of Solution

Calculation:

The time is calculated below.

  $\begin{array}{l}=\frac{7}{2.5w}\\ =\frac{7\times 60}{2.5\left(3.5\right)}\\ =48\text{ min}\end{array}$

Conclusion:

The time spends to go and return back from her friend’s house is $48\text{ min}$