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$[[,$Merchandise,$\backslash$table$[[$Freight$],[$Paid by Seller$]],$Freight Terms,$\backslash$table$[[$Credit for$],[$Refunds and$],[$Allowances$]]],[$a$.,$$$120,800,$$$1,300,$FOB shipping point, $\frac{1}{10},\frac{n}{30},$$$20,100$