Question

Question is in image

Answer 1

To find the answer, we have to find the slope of the line.

`m=(y_2-y_1)/(x_2-x_1)`

Let's replace the points (2,20) and (8,80), where

`\begin{gathered} x_1=2 \\ x_2=8 \\ y_1=20 \\ y_2=80 \end{gathered}`
`m=(80-20)/(8-2)=(60)/(6)=10`

This means that the tip earned increases at a rate of $10 per hour.

Hence, the correct answer is B.