Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales for Item PK95 are as follows: January 11 Inventory 59 units @ $16 Sale 48 units Purchase 56 units @ $18 Sale 20 units Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on January 25 and (b) the inventory on January 31.. a. Cost of merchandise sold on January 25 b. Inventory on January 31, 9 13 25