Perpetual Inventory Using FIFO

Beginning inventory, purchases, and sales for Item PK95 are as follows:

July 1		Inventory	36 units @ $23
9		Sale	25 units
13		Purchase	31 units @ $26
28		Sale	16 units

Assuming a perpetual inventory system and using the first-in, first-out (FIFO) method, determine (a) the cost of merchandise sold on July 28 and (b) the inventory on July 31.

a. Cost of merchandise sold on July 28	$
b. Inventory on July 31	$

PLEASE SHOW WORK SO I CAN UNDERSTAND IN FUTURE