At a local pound, 40% of the animals sheltered are cats and 15% of the cats are black. If there are 30 black cats at the pound, how many animals are sheltered there?
number of cats = x
.15x = 30
x = 30/.15 = 200
but that is 40% of all animals
number of animals = 200/.40 = 500
check:
number of cats = 4/10(500) = 200
black cats = 15/100(200) = 30