MATH 120 Lecture 15: Chapter 8.1 Factorial
Document Summary
Factorials are just an expression used to show what numbers are being multiplied together instead of writing the entire chain. As you can see in this chain, it starts multiplying with 5 all the way down to 1. = 20 x 19 x 18 x2 x 1 = 2. 43 x. In this chain, it starts multiplying with 20 all the way down to 1. There are m1 ways to make choice 1. There are also m2 ways to make choice 2. So, there are mr ways to make choice r. Therefore, m1 m2 mr ways to make an entire sequence of choices. A license plate will have 3 letters, then 3 numbers. So, there are 26 ways to make each "letter choice" (since there"s 26 letters in the alphabet). Also, there are 10 ways to make each "number choice" (0 - 9). Now, we just multiply the amount of ways possible by each choice.
