Brooks Expeditions provides guided fishing tours. The company charges $$160$ per person but offers a $15\%$ discount to parties of four or more. Consider the following transactions during the month of May.

May $2$ Charlene books a fishing tour with Brooks Expeditions for herself and four friends at the group discount price $($$$680=$ $$136\backslash$times $5).$ The tour is scheduled for May $7.$

May $7$ The fishing tour occurs. Brooks Expeditions asks that payment be made within $30$ days of the tour and offers a $4\%$ discount for payment within $15$ days.

May $9$ Charlene is upset that no one caught a single fish and asks management for a discount. Brooks Expeditions has a strict policy of no discounts related to number of fish caught.

May $15$ Upon deeper investigation, management of Brooks Expeditions 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 $40\%$ of the amount due.

May $20$ Brooks Expeditions receives the amount owed by Charlene.