Freight terms

Determine the amount to be paid in full settlement of each of two invoices, $($a$)$ and $($b$),$ assuming that credit for returns and allowances was received prior to payment and that all invoices were paid within the discount period.

$\backslash$table$[[,\backslash$table$[[$Merchandise$],[($Invoice Amount$)]],\backslash$table$[[$Freight$],[$Paid by Seller$]],$Freight Terms,$\backslash$table$[[$Returns and$],[$Allowances$],[($Invoice$],[$Amount$)]]],[$a$.,$$$24,000,$$$300,$FOB destination, $\frac{1}{10},\frac{n}{30},$$$2,000$