Reading
Read Section 1.3 of Carlton and Devore, pages 18–25. We will not use the tree diagrams of Section 1.3.2, page 20, much, but they will help your understanding of how to systematically count all the possible options.
The important notions are:
- Permutations
- Combinations.
Videos
The following video gives a systematic way of thinking about permutations and combinations:
The following video works through Exercise 49 from Section 1.3.
Exercises
For practice, you can try your hand at the following representative exercises from Section 1.3: 31, 33, 37, 39, 43, and 45. (You will get the idea halfway, and don't have to make them all!)