##28.23## miles per gallon
For this we need to convert kilometers into miles and liters into gallons.
As there are ##0.621371## miles in each kilometer we have ##0.621371xx12=7.456452## miles.
Further there being ##0.264172## gallons in each liter means
##12## ##(km)/L## is equivalent to
##7.456452/0.264172## miles per gallon or ##28.23## miles per gallon.