Shelia's car goes 150 miles on 5 gallons of gas. Derek's car goes 105 miles on 3 gallons of gas. How many more miles does Derek's car go per gallon of gas than Sheila's car?
A. 5
B. 65
C. 30
D. 35
To find the difference in mileage per gallon between the two cars, we can divide the difference in mileage by the difference in gallons of gas used.
Derek's car goes 105 - 150 = <<105-150=-45>>-45 miles less than Shelia's car.
Derek's car uses 3 - 5 = <<3-5=-2>>-2 gallons less gas than Shelia's car.
Thus, Derek's car goes 45 / 2 = <<45/2=22.5>>22.5 miles more per gallon than Shelia's car.
Thus, the answer is C. 30.