Answer:
Car C
Explanation:
Miles per gallon = miles traveled / gallon of gas used
Miles per gallon :
Car A = 19 / 1 = 19 miles per gallon
Car B = 39 / 3 = 13 miles per gallon
Car C = 42 / 2 = 21 miles per gallon
Car D = 48 / 3 = 16 miles per gallon
Car with most miles per gallon is car C