Question

A family has two cars. The first car has a fuel efficiency of 40 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 1025 miles, for a total gas consumption of 35 gallons. How many gallons were consumed by each of the two cars that week?

Answer 1

Let us assume the number of gallons consumed by car A = x gallons
Let us assume the number of gallons consumed by car B = (35 - x) gallons
Then
Distance covered by car A = 40x
Distance covered by car B = 15(35 - x)
So
40x + 15(35 - x) = 1025
40x + 525 - 15x = 1025
25x = 500
x = 20
Then
Amount of gas consumed by car A = 20 gallons
Amount of gas consumed by car B = 15 gallons.