Question

Keith sold half of his comic books and then bought 9 more. He now has 15. How many did he begin with?

Answer 1

Keith had `12` comic books to begin with.

Explanation:

If we represent the original number of comic books as `x`, we can write the following equation:

`x/2+9=15`

Subtract `9` from both sides.

`x/2=6`

Multiply both sides by `2`.

`x=12`