Answer
4.5 gal
Work Step by Step
18 qt to gallons
Use a unit fraction with gallon (the unit for your answer) in the numerator, and quarts (the unit being changed) in the denominator. Because 4 quarts (qt) = 1 gallon (gal), the necessary unit fraction is (1 gal)/(4 qt)
Multiply 18 qt times the unit fraction.
18 * (1 gal)/(4 qt) = 9/(2 ) gal = 4.5 gal