Outdoor Expo provides guided fishing tours. The company charges $120 per person but offers a 10% discount to parties of four or more. Consider the following transactions during the month of May.

May 2 Charlene books a fishing tour with Outdoor Expo for herself and four friends at the group discount price ($540 = $108 × 5). The tour is scheduled for May 7.
May 7 The fishing tour occurs. Outdoor Expo asks that payment be made within 30 days of the tour and offers a 5% discount for payment within 15 days.
May 9 Charlene is upset that no one caught a single fish and asks management for a discount. Outdoor Expo has a strict policy of no discounts related to number of fish caught.
May 15 Upon deeper investigation, management of Outdoor Expo discovers that Charlene’s tour was led by a new guide who did not take the group to some of the better fishing spots. In concession, management offers a sales allowance of 30% of the amount due.
May 20 Charlene pays for the tour after deducting the sales allowance.