molly and kali are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. molly sold 12 small boxes of grapefruit and 5 large boxes of grapefruit for a total of $200. kali sold 4 small boxes of grapefruit and 10 large boxes of grapefruit for a total of $200. what is the cost of one small box of grapefruit and one large box of grapefruit?