Answer
a.) 18 qt
b.) 0.75 lb
Work Step by Step
a.) 4 1/2 gal = 18 qt
You are converting from a larger unit to a smaller unit (a gallon is larger than a quart), so multiply.
Because 1 gal = 4 quarts, multiply by 4.
4 1/2 gal= 9/2 * 4/1 = 18 qt
b.) 12 oz = 3/4 lb = 0.75 lb
You are converting from a smaller unit to a larger unit (a ounce is smaller than a pound) so divide.
Because 16 ounces (oz) = 1 pound (lb), divide by 16.
12 oz = 12 / 16 = ¾ or 0.75 lb