Chapter 12.1, Problem 1E

In Exercises 1–4, you are selecting from the set $\text{W}=\left\{\text{University of }\left(\text{C}\right)\text{onnecticut, }\left(\text{D}\right)\text{uke, University of}\left(\text{F}\right)\text{lorida, University of}\left(\text{N}\right)\text{orth Carolina}\right\}$ of teams that have won the national championship in Division 1 men's basketball multiple times since 2000. List all the ways you can make each selection.

Select two teams without repetition; order is not important. For example, DD is not allowed, and CD is the same as DC.