Question

A family has two cars. The first car has a fuel efficiency of 20 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. During

one particular week, the two cars went a combined total of 1325 miles, for a total gas consumption of 75 gallons. How many gallons were consumed by each of
the two cars that week?

Answer 1

40 and 35

Explanation:

If we say the first car uses x gallons then the second car must use 75 - x gallons.

The distance travelled is the number of gallons used * the efficiency of the car.

20x + 15(75-x)=1325

20x + 1125 - 15x = 1325

5x = 200

x = 40

This means that the first car uses 40 gallons and the second car uses 75-40= 35 gallons