perpetual inventory system_calculate ending inventory

Using the following information to calculate ending inventory on (a) a LIFO basis (b) FIFO basis and (c) average-cost basis. Assume a perpetual inventory system. 

Round answers to the nearest dollar.

Dec. 1 Beginning inventory 70 units @ $28
Dec. 9 Purchases 30 units @ $32
Dec. 17 Sales 25 units
Dec. 22 Purchases 15 units @ $36
Dec. 27 Sales 40 units