Beginning inventory, purchases, and sales for an inventory Item are as follows: Sep. 1 Beginning Inventory 21 units $15 5 Sale 12 units 17 Purchase 24 units $18 30 Sale 22 units Assuming a perpetual inventory system and the first in, first-out method, determine (a) the cost of the goods sold for the September 30 sale and (b) the inventory on September 30 a. Cost of goods sold b. Inventory, September 30