Determining amounts to be paid on invoices

Determine the amount to be paid in full settlement of each of the following invoices, assuming that credit for returns and allowances was received prior to payment and that all invoices were paid within the discount period:

Invoice Merchandise

Invoice Amount Freight

Paid by Seller FOB Customer Returns

and Allowances

a$.$ $$15,900$ FOB destination, n$/30$ $$800$

b$.10,100$ $$400$ FOB shipping point, $2/10,$ n$/301,200$

c$.7,900$ FOB shipping point, $1/10,$ n$/30700$

d$.3,000100$ FOB shipping point, $1/10,$ n$/30400$

e$.2,500$ FOB destination, $1/10,$ n$/30$