Addison, Inc. uses a perpetual inventory system. Information about one inventory item for the month of September follows.
Date Line Item Description Units and Cost
Sep. 1 Inventory 20 units at $20
4 Sold 10 units
10 Purchased 30 units at $25
17 Sold 20 units
30 Purchased 10 units at $30
If Addison uses FIFO, the September 30 inventory is
