Question

A family has two cars. The first car has a fuel efficiency of 35 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 1825 miles, for a total gas consumption of 75 gallons. How many gallons were consumed by each of the two cars that week?

Answer 1

1) 35 gallons by the first car 2) 40 gallons by the second car

Explanation:

Suppose the first car used x gallons, when the second car used the rest- 75-x

If the first car's efficiency is 35 miles per galon, its milleage is 35*x, the second car's milleage is 15*(75-x). And the summary milleage is equal to 1825.

35x+15(75-x)=1825

35x+1125-15x= 1825

20x=700

x=35- gallons consumed by the first car,

75-35=40- gallons consumed by the second one