The Four Suits Problem and the Inclusion-Exclusion Principle

In this exciting lecture, I present the solution to an introductory-level probability problem which illustrates the Inclusion-Exclusion Principle, an important idea in combinatorics. I plan on elaborating further on this principle in the future; I do not even mention it by name in this video. Playing cards are awesome. You can learn a lot from them if you know where to look.