Chapter 2: Counting
One of the first things you learn in mathematics is how to count. Now we want to count large collections of things quickly and precisely. For example:
- In a group of 10 people, if everyone shakes hands with everyone else exactly once, how many handshakes took place?
- How many ways can you distribute girl scout cookies to boy scouts?
- How many anagrams are there of “anagram”?
Before tackling questions like these, let's look at the basics of counting.
Discrete Mathematics: An Open Introduction, 3rd edition, by Oscar Levin (discrete.openmathbooks.org), licensed under CC BY-SA 4.0; this adaptation is distributed under the same license. License: CC-BY-SA-4.0.