Question

A family has two cars. The first car has a fuel efficiency of 30 miles per gallon of gas and the second car has a fuel efficiency of 15 miles per gallon of gas. During one particular week, the two cars went a combined total of 825 miles, for total gas cumsumption of 40 gallons. How many gallons were consumed by each car

Answer 1

Number of gallons consumed by first car = 15 gallons

Number of gallons consumed by second car = 25 gallons

Explanation:

Given that:

Fuel efficiency of first car = 30 miles per gallon

Fuel efficiency of second car = 15 miles per gallon

Total distance traveled = 825 miles

Total gas consumption = 40 gallons

To find:

Number of gallons consumed by each car = ?

Solution:

Let the number of gallons consumed by first car =
`x` gallons

As per question statement, number of gallons consumed by second car:

`40-x`

Number of miles covered by a car = Fuel efficiency
`*` Number of gallons consumed

Number of miles covered by first car = 30
`*`
`x`

Number of miles covered by second car = 15
`*` (
`40-x`)

Using the given statement:

`30x+15(40-x)=825\\\Rightarrow 30x+600-15x=825\\\Rightarrow 15x=225\\\Rightarrow x =15\ gallons`

Therefore, Number of gallons consumed by first car = 15 gallons

Number of gallons consumed by second car = 40 - 15 = 25 gallons