Perpetual Inventory Using Firo teginning inventory, purchases, and sales for Item Zetas are as follows: Inventory 51 units 20 2 ale 40 units 15 Purchase 50 units $22 24 Sale 16 units Assuring a perpetual inventory system and use the first in first-out (FFO) method, determine (a) the cost of goods solt on October 24 and (b) the installer an a. Cost of goods sold on October 24 b. Inventory on October 31