Dr. Posten is a veterinarian one week she treated 20 dogs 16 cats and 11 birds some owners had more than one pet. How many owners had only a dog as a pet

maximum area = xy = (16)(32) = 512 ft2

to maximize the area of the garden, the side of the fence parallel to the side of the house should be 32 ft long, and the other two sides should both have length 16 ft.'

source

-6 is the correct option from the above given options