Baking Brownies- Number

Monique wants to bring in brownies for her birthday, so that all 24 students can have one for a mid-morning snack and one for a mid-afternoon snack. You have to go to the store to buy brownie mix. There are 15 brownies in one batch. One batch of brownies requires 3 1/2 cups of mix. There are 5 cups of mix in a box of brownie mix. How many boxes of brownie mix are needed?

Explain how you arrived at your answer.

Extension: If Monique wanted to bring in brownies for all 96 students in her grade, how many boxes of brownie mix would she need?