Answer
$\frac{1}{30}$ gallons of gasoline per mile driven
This is around $0.033$ gallons of gasoline per mile driven.
Work Step by Step
After driving 60 miles, the car has consumed 2 gallons of gasoline.
After driving 300 miles, the car has consumed 10 gallons of gasoline.
The increase in gasoline consumed is:
$=10-2=8$ gallons
The increase in distance driven is
$=300 - 60=240$ miles driven
Thus, the average rate is:
$=\dfrac{8\text{ gallons of gasoline}}{240 \text{ miles driven}}=\frac{1}{30}$ gallons of gasoline per mile driven
