Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item Zeta9 are as follows: Oct. 1 Inventory 39 units @ $20 7 Sale 26 units 15 Purchase 24 units @ $22 24 Sale 20 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of goods sold on October 24 and (b) the inventory on October 31. a. Cost of goods sold on October 24 b. Inventory on October 31