Together Adam and Jackie have 12 apples. He has 9 apples more than Adam and Jackie together do. Adam has 8 more apples than Jackie. How many apples does He have?
:

1) Together Adam and Jackie have 12 apples.

2) He has 9 apples more than Adam and Jackie together do.

3) Adam has 8 more apples than Jackie.

This means that He must have 9 + 8 = 17 apples.