erpetual inventory using FIFO eginning inventory, purchases, and sales for Item Zeta9 are as follows: Oct. 1 Inventory Oct. 7 Sale 35 units @ $21 29 units Oct. 15 Purchase Oct. 24 Sale 28 units @ $22 12 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