You need to make sure that each bag has the combination of items and they want you to list as many ways as you can think of on how to solve this. One way is:
Divide 48(brownies) by 2, you get 24, and if you divide 64(cookies) by 2, you get 32. So you will need 2 boxes ( since we divided both the numbers by 2 ) and each box will have 24 brownies and 32 cookies in each.
2nd way:
Divide 48( brownies) and 64(cookies) by 4, and you will get 12(brownies) and 16(cookies), so you will need 4 boxes with 12 brownies and 16 cookies in each since we divided the numbers by 4.
So basically, you can keep doing this until no more numbers equal to 48 or 64 when you divide them. And the number you divide them with is how many boxes you will need. Hope this helps.