a$.$ Purchased $$25,000$ of merchandise from Wright Co$.$ on account, terms $\frac{2}{10},\frac{n}{30}.$

b$.$ Paid the amount owed on the invoice within the discount period.

c$.$ Discovered that $$5,000$ of the merchandise purchased in $($a$)$ was defective and returned items, receiving credit.

d$.$ Purchased $$4,100$ of merchandise from Wright Co$.$ on account, terms $\frac{n}{30}.$

e$.$ Received a refund from Wright Co$,$ for return in $($c$)$ less the purchase in $($d$).$