36/9=4
5*4=20 puppies and 4*4=16 kittens.
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ratio 5:4. This means that there is a number that if you multiply it by 5 you get the number of puppies, and if it is multiplied by 4 you get the number of kittens. This is like 5x+4x, which is 9x. so, just solve 9x=36 and get x.
