Please explain how you got the numbers.

Beginning inventory, purchases, and sales for Product XCX are as follows: Oct. 1 Beginning Inventory 23 units $11 Oct. 5 Sale 13 units Oct. 17 Purchases 21 units $12 Oct. 30 Sale 16 units Assuming a perpetual inventory system and the last-in, first-out method, determine (a) the cost of the merchandise sold for the October 30 sale and (b) the inventory on October 31. Cost of merchandise sold $ Inventory, October 31 $