1. Warm Up
Melanie is choosing an outfit for a job interview. She has four dresses, three blouses, five pairs of pants and three pairs of shoes to choose from. How many possible outfits can Melanie wear?
In a certain state, automobile license plates display two letters followed by four digits. How many such plates are possible if repetition of the digits is not allowed?

2. HW Check Fundamental Counting Principle Worksheet

3. From Friday…
In how many different ways can a race with six runners be completed? Assume there is no tie.
2nd period only

4. Today, we are going to talk about COMBINATIONS!!
Unit 2, Day 2

5. Combinations Order does not matter
The number of combinations of r selected items from a set of n items at a time is:
C =
N- how many options you have
R- how many you want to pick

6. Example 1 There are seven books on your summer reading list.
How many ways can you choose five books to read?

7. Example 2 A magazine company has 20 subscriptions to choose from.
In how many ways can you order 4 magazines?

8. Your Turn!
Of the 20 books on your reading list, in how many ways can you choose 7 books?
In how many ways can 3 pizza toppings be chosen from 12 available toppings?
In how many ways can 7 students from a class of 30 be chosen for a field trip?

9. Calculator Shortcut…
Notation: C(n,r) “n choose r” nCr
Remember N- how many options you have
R- how many you want to pick
Ex) Let’s check our first example (7 books, choose 5) using the calculator.

10. Coming up…
Tutoring today from 3:15 – 4:30! Please sign up on the clipboard if you are planning to stay! HW Tonight – Combinations Worksheet Quiz – Thursday!