7.4 Under first-come, first-served, Dana will have to postpone his lesson. Since Dana would be willing to pay up to $10 to avoid postponing it, he will be better off if the pro asks for a contribution of, say, $8, and then lets him take Bill’s place at the scheduled time. The pro could then give $4 to Bill, which would make him $1 better off than if he had not postponed his lesson. The remaining $4 of Dana’s payment could be distributed by giving $1 each to Ann, Carrie, Earl, and the tennis pro.