Answer:
3
Explanation:
To answer these sorts of questions we have to go backwards and do the opposite.
1. If the result is 12 we need to add (opposite of subtract) 3. This makes 15.
2. If the opposite of multiply is divide, we do 15÷5=3.
We can check our answer by following it on the equation. 3 multiplied by 5 is 15. 15 subtract 3 is 12 which is the result. Therefore 3 is the number.