Compute the amount to be paid for each of the four separate invoices assuming that all invoices are paid within the discount period. {:[" Merchandise "],[" (gross) "]:} Terms Payment a. $ 8,400 2//10,n//60 b. $ 25,100 1//15,n//90 c. $ 81,800 1//10,n//30 d. $ 18,500 3//15,n//45