Agrocery store stocks shelves with 80 cartons of strawberries before the store opens. for the first 3 hours the store is open, the store sells 10 cartons per hour. over the next 2 hours, no cartons of strawberries are sold. the store then restocks 10 cartons each hour for the next 2 hours. in the final hour that the store is open, 20 cartons are sold. graph the function.