## Thinking Mathematically (6th Edition)

The provided set of films is: {Avatar, The Avengers, Titanic, The Dark Knight, Star Wars, Shrek 2, E.T. the Extra Terrestrial} The number of ways to view some, all, or none of these films is equal to the number of subsets of the given set. A set of $n$ elements has $2^n$ subsets; therefore, our set has: $2^7=128$ subsets. There are 128 viewing options.