Hey there!
The correct answer is 30 miles per gallon.
If he can drive 270 miles on 9 gallons, we want to find the unit rate, or miles per gallon. We can do this by dividing 270 by 9. To make it easier, we will take off the zero, and do 27/9, which is 3. Now we add the 0 back on, which gives us 30. Therefore, his average mileage is 30 miles per gallon.
Have a terrificly amazing day! :D
