Problem:
At the beginning of a trip, the mileage odometer read miles. The driver filled the gas tank wtth gallons of gasoline. During the trip, the driver filled his tank again with gallons of gasoline when the odometer read . At the end of the trip, the driver filled the tank agaln with gallons of gasoline. The odometer read . To the nearest tenth, what was the car's average miles-per-gallon for the entire trip?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The trip was long and gallons of gasoline were used during the trip. Thus the average number of miles per gallon was . Note that the gallons needed to fill the tank at the start of the trip had no effect on the answer. No matter how many gallons were needed to fill the tank at the start, the average miles per gallon for the trip would be .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions