Monte Vista uses the perpetual inventory system. At the beginning of the quarter, Monte Vista has $60,000 in inventory. During the quarter the company purchases $15,800 of new inventory from a vendor, returned $1,400 of inventory to the vendor, and took advantage of discounts from the vendor of $400. At the end of the quarter the balance in inventory is $53,000. What is the cost of goods sold?

$21,000

Explanation:

The movements in  a company's inventory balance at the start and end of an accounting period is as a result of purchases and sales.

This may further be influenced by purchase returns, discounts and rebates (which are all considered in getting the net purchase).

Mathematically,

opening balance + net purchases - cost of goods sold = closing balance

$60,000 + ($15,800 - $1,400 - $400) - cost of goods sold = $53,000

Cost of goods sold = $21,000