sydney retailing (buyer) and troy wholesalers (seller) enter into the following transactions. may 11 sydney accepts delivery of $32,500 of merchandise it purchases for resale from troy: invoice dated may 11, terms 3/10, n/90, fob shipping point. the goods cost troy $21,775. sydney pays $565 cash to express shipping for delivery charges on the merchandise. may 12 sydney returns $1,300 of the $32,500 of goods to troy, who receives them the same day and restores them to its inventory. the returned goods had cost troy $871. may 20 sydney pays troy for the amount owed. troy receives the cash immediately.