please answer

1\2 Inventory 300 units 3000$ 2\2 purchases 500 units 7500$ 3\2 sold units 600 units for 12000 $ 5\2 purchases 400units 1.4$per unit 6\2 units sold 450 units for2.5 for each 1) under perpetual system-FIFO metthod and WA Method compute gross margin? 2)under periodical system compute gross margin using FIFO and WA