**There were some chocolate and strawberry cookies. The number of chocolate cookies was 5/8 the number of cookies. After A ate some of the chocolate cookies and 3/7 of the strawberry cookies, the number of strawberry cookies left was 7/17 of the cookies left. A bought 120 chocolate cookies and 480 strawberry cookies. In the end, there were an equal number of chocolate and strawberry cookies left. How many chocolate cookies did A eat?**

**Joke: Who in the right mind eat so many cookies? **

Source: Conquer Problem Sums 6 standard edition