
Krista G. answered 11/15/19
Professional Editor, Writer - English + Sociology
Simply put, you only need the information for Store A. So if you're paying for 3 boxes and getting 4, you're paying 3/4 of the price of each box. Let's pretend each cereal box cost $1. If you pay $3 to get $4 worth of cereal, you're paying $3 (actual) / $4 (regular) = 3/4 or .75 or 75% of the normal cost per box. It's important to note that you have to pay attention to the fact that he's getting 4 boxes, not just 3! So make sure you include the 4 in your equation.
I hope that helped! :)