1. Warm up 7! 4!
Answers:
5040 24
840 6
360 3) 4) 5)

2. Combinations 14.5 A combination is:
A selection of objects in which order is not important!
Example of combination: You order a sausage and mushroom pizza over the phone. After hanging up more friends show up to your house so you call back to order another pizza. This time you order a mushroom and sausage pizza. How can you tell them apart? Are they different?
The pizza are the same because order does not matter! They are both delicious! combination…..

3. Permutation review: Order matters…
Examples: Relay teams, order of books on a shelf, order of letters
In combinations order does not matter…so we have to get rid of the duplicates…..
We eliminate the duplicates by adding 1 small step to the denominator
Combination Equations =

4. Examples of Combinations
1) The number of combinations of 4 objects taken 2 at a time.
A combination is written in this manner:
n = 4 This is the number of items
r = how many you take
Using the formula
4 items taken 2 at a time results in 6 different ways

5. Example 2
Lunch Menu: You order a sandwich at a restaurant. You can choose 2 side dishes from a list of 8. How many combinations of side dishes are possible?
2 choices
8 sides
There are 28 different combinations of side dishes you can order.

6. Practice 14C2 2) 3) 4)Count the combinations of two
letters from the list of A, B, C, D.

7. More Practice
You win four tickets to a concert. In how many ways can you choose 4 friends out of a group of 9 to take with you to the concert?
At an ice cream shop, you purchase a bowl of ice cream with two scoops of different flavors. How many combinations can you make if the shop has 22 flavors?
126 different ways
231 different combinations

8. Homework
Worksheet 14.5