Question

the fuel efficiency rating for a certain car is 28 mi/gal on the highway and 20 mi/gal in the city. during one week the car traveled 220 mi and used 9 gal of fuel. how much fuel?

Answer 1

4 gallon fuel was used for city driving and 5 gallon fuel used on the highway.

Explanation:

Consider the provided information.

Let x is the gallon used in highway and y is the gallon used in city.

The fuel efficiency rating for a certain car is 28 mi/gal on the highway and 20 mi/gal in the city.

Thus,
`28x+20y=220`

They used total 9 gallon.

`x+y=9`

`x=9-y`

Substitute the value of x in
`28x+20y=220`.

`28(9-y)+20y=220`

`252-28y+20y=220`

`8y=32`

`y=4`

Substitute the value of y in
`x=9-y`.

`x=9-4=5`

Hence, the value of x is 5 and the value of y is 4.

4 gallon fuel was used for city driving and 5 gallon fuel used on the highway.