Answer: 97 stickers
Explanation:
Marie has 87 stickers in her collection.
Each week she collects 5 and gives away 3.
The total number of stickers she gains per week is therefore:
= 5 - 3
= 2 stickers per week
In 5 weeks therefore, she would have collected:
= 2 * 5
= 10 stickers
Add that to the original number:
= 87 + 10
= 97 stickers