Question

A truck can be rented from company. How many miles must be driven in a day to make the rental cost for a company a better deal than company b

Answer 1

We have the following parameter

Company A

The charges is given by

`\begin{gathered} \text{ 120 + }0.8x \\ \text{where x is the number of miles} \end{gathered}`

Company B

The charges is given by

`60+0.9x`

To determine how many miles it will take for the rental cost of company A to exceed B, we will set up the inequality

`120+0.8x<60+0.9x`

To find the number of miles, we will make x the subject of the formula

`\begin{gathered} 120-60<0.9x-0.8x \\ 60<0.1x \end{gathered}`

Re-arranging

`\begin{gathered} 0.1x>60 \\ x>(60)/(0.1) \\ x>600\text{ miles} \end{gathered}`

Therefore, for the rental cost of company A to be better than company B, the number of miles driven in a day must be greater than 600 miles