Chapter 4 Basic Enumeration
The goal of the next two chapters is to learn techniques for counting variably complex sets. Consider ProblemĀ 4.1.1.
Much of the skill is in finding a known model that has the same count. The following sections will demonstrate models and also present problems for you to count.
Frequently a problem can be counted more than one way (more than one model). Noting when two or more models can be used is also an important aspect of combinatorics.