Answer:
3
Step-by-step explanation:
You could make this problem into an equation. For example, you would give the number of cats x. A cat only has one tail. Therefore, the number of tails would also be x. And there are 9 more legs than tails. Also, a cat has 4 legs. So, 9 + x = 4x. Simplify the equation, and it gives you: x = 3.