The Pit BBQ food truck sells two combo packs of ribs and brisket. Combo A contains 10 oz of brisket and 16 oz of ribs and sells for $21.25. Combo B contains 20 oz of brisket and 8 oz of ribs and sells for $30.00. They plan to use no more than 400 oz of brisket and 384 oz of ribs and they want to sell at most 28 combo packs. How many of each combo should be made to maximize revenue ?