Assume that if Cody books the group traveling to the Upper Keys, then he will be able to book another group for the return trip to the Miami airport. Unfortunately, Cody will not be able to book another group for the return trip if he goes to the Lower Keys. How does this piece of information affect your answer to part [a]? In other words, which group should Cody book, and by how much will his overall (business + personal) income increase by booking this group