Sally's pet grooming business charges $5 per cat and $10 per dog for a pet bath. She earned $550 for pet baths last month. If 20 of those were cats, how many were dogs?
so she has $550 and she did 20 cats and it costs $5 per cat and 5 x 20 is $100 and $550 - $100 = 450 and 450 divided by 10 ( because it's $10 per dog) is 45.
