Math question: what is the price of gas per mile if...?

Question

If your car gets 18 mi to the gallon and gasoline costs 4.00 dollars a gallon, then what is the price per mile?

Please tell me how you arrive at this, so i can do it myself next time. Thank you~!

Answer 1

Instead of looking at it as 18 miles to the gallon.

Look at it this way:  For 4 dollars you get 18 miles.

4 dollars / 18 miles = .22 cents a mile.

Answer 2

18 miles = 4$

so 1 mile = ?

Make a proportion

18/1 = 4/x

cross multiply

18x=4

x=4/18

=.222222222 repeating

so the answer is approximately 22 cents per mile.

Answer 3

It would be .22222 repeating. All you do is divide 4 by 18. Think of it like this, Price per gallon, 4 by 18.