Sally, an accounting technician, works on the sales ledger in Big Foods, a food wholesaler. One of its customers, Fare Foods, is owned by Sallys brother. Fare Foods has placed a large order and, like all other customers, receives a 2% prompt payment discount on invoices settled within 14 days. The usual practice within the accounts department, which applies to all customers, is that the date recorded in the sales ledger is the date on which the payment is received in the accounts department (which must always be the same day that payment is received in the post or delivered to the reception desk). However, there are often one or two days between the cheques arriving at Big Foods and their eventual processing. In addition, cheques and cash received by Big Foods are banked only twice per week, on Wednesdays and Fridays