Question

A brand new motorcycle gets 70 miles per gallon of gas. If the motorcycle drives 520 miles before running out of gas, how much gas started in the tank? Write you answer as a mixed number.

Answer 1

`x=7 (3)/(7)` gallons

Explanation:

So we are given:

70 miles -> 1 gallon is used.

520 miles -> x gallons is used.

Set up a proportional to solve.

I lined up everything already above:

`(70)/(520)=(1)/(x)`

Cross multiply:

`70(x)=520(1)`

`70x=520`

Divide both sides by 70:

`x=(520)/(70)`

Reduce the fraction (divide top and bottom by 10):

`x=(52)/(7)`

How many 7's are in 52? 7 because 7(7)=49

How much is left over after seven 7's go into 52? 52-49=3

So the answer as a mixed fraction is:

`x=7 (3)/(7)`