Trying to figure out gas price to miles

Question

If gas is $4.30 how much should I charge for 13 miles

Answer 1

$4.30 for a gallon

13 miles

total cost for 13 miles depends on the gas mileage of the vehicle

13 miles per gallon, and it costs $4.30 total for 13 miles

26 mpg and it costs 4.3/2 = $2.15 total for 13 miles

20 mpg and it costs (13/20)4.3 = $2.795 = $2.80 total for 13 miles

40 mpg and it costs 2.795/2 = $1.40 total for 13 miles