Perpetual Inventory Using FIFO Beginning inventory, purchases, and sales data for portable game players are as follows: Apr. 1 Inventory 180 units at $40 10 Sale 140 units 15 Purchase 210 units at $42 20 Sale 170 units 24 Sale 60 units 240 units at $46 30 Purchase The business maintains a perpetual inventory system, costing by the first-in, first-out method.