John buys eight packs of cookies at the grocery store. The cookies are on sale for 50 cents off per pack. He spends $20. Equation can be used to find the original cost of a box of cookies, c?
Let c be the original cost of a pack of cookies. The discounted cost of a pack of cookies is c - $0.50. John bought 8 packs of cookies, so the total cost is 8 * (c - $0.50). We know that the total cost is $20. Therefore, we can write the equation as follows:
8 * (c - $0.50) = $20