Final answer:
Brooke saved 27.5 gallons of water compared to Avery by using a pressure washer, which is equivalent to 110.0 quarts of water.
Step-by-step explanation:
The difference in water usage between Brooke and Avery can be found by subtracting the amount of water Avery used from the amount Brooke used. Therefore, 40 - 12.5 = 27.5 gallons of water saved. Since there are 4 quarts in a gallon, we can convert the gallons saved into quarts by multiplying by 4. So, 27.5 * 4 = 110.0 quarts of water saved.