If each person privately rented a movie to watch on their own, how many would each person rent?

If each person privately rented a movie to watch on their own, how many would each person rent? (b) Suppose that each roommate enjoys watching movies together just as much as alone. Within a dorm room, then, is the showing of a movie a public good? Why or why not? (c) If it costs $8 to rent a movie, how many should they rent to maximize total surplus?