Perpetual inventory, using firo Beginning inventory, purchases, and sales for ftem Zeti9 are as follows: Assumang a perpetual inventory system and using the first-in, frst-out (f)Fo) method, deternane (o) the cost of goods sold on October 24 and (b) the inventory on October 31 a. Cost of goods wold on October 24 b. Inventory on October 31 x