To find the unit rate of miles per gallon, you can divide the total miles driven by the total gallons of gas.
Lars drives 330 miles on a full tank of gas, which is 15 gallons.
The calculation is as follows:
\[ \text{Miles per gallon} = \frac{\text{Total miles}}{\text{Total gallons}} = \frac{330 \text{ miles}}{15 \text{ gallons}} = 22 \text{ miles per gallon} \]
Therefore, Lars gets 22 miles per gallon.