bad debt Q

Brunner Company had the following balances on January $1,2020$: Accounts Receivable $$120,000$

Allowance for doubtful Accounts $-14,000$

During the current year the company recorded the following transactions:

$$ Trans. $1$ Sales on credit for the year $$220,000.$

$$ Trans. $2$ Customers returned $$8,000$ of merchandise for credit.

$$ Trans. $3$ Collections from customers $$180,000.$

$$ Trans. $4$ Write$-$off during the year $$16,000.$

$$ Trans. $5$ Collected $$4,000$ of previously written$-$off accounts.

$$ Bruner estimates its AFDA balance at year$-$end at $15\%$ of Accounts Receivable balance.

c$)$ What is the amount that will be reported as Bad Debt Expense for this year? $$18400*$how did they get this answer pls explain I dont understand how to calculate bad debt.