Help please!

Monica goes to Costco to buy groceries for the next couple months. Monica normally purchases boxes of applesauce cups (15 cups) and fruit snacks (22 snacks) as snacks for her child's lunch (1 snack per day). A box of applesauce costs $10 and a box of fruit snacks costs $12.50. Monica only has $100 dollars to spend and wishes the snacks to last for at least 120 days.

1. Write a system of equations for this problem.
2. Should Monica buy 5 boxes of applesauce and 3 boxes of fruit snacks? Why or why not?