At my office, 16 people own cats, 9 people own dogs, and 2 people own both cats and dogs. How many people own a cat or a dog?
16 + 9 - 2 =
So we can subtract 2 from both 16 and 9 to get 14 and 7. Then we add these and get 21. So 21 is the final answer.
+189 
