1. 5.2 Combinations

2. As a Group If we want to elect the 2 coolest people in the classroom and call them, co-coolies, how many different pairs can we pick? – How about choosing 2 from only 2? – How about choosing 2 from only 3?

3. Combinations the number of ways to select a certain number of things when order does not matter!!! Permuations => Order does matter Combinations => Order does matter

4. Example In how many ways could Mistine, Eric, Bo, and Ryan, and Kate fill the positions of President, Vice-President, and Secretary? In how many ways could these same 5 people form a committee with three members? How are the numbers of ways in the previous 2 questions differ?

5. Combination When the order of something does not matter, we divide the number of permutations by the number of ways to arrange the items

6. Combination

8. Example How many different sampler dishes with 3 different flavors could you get at an ice-cream shop with 31 different flavours?

9. Example A ballet choreographer wants 18 dancers for a scene. – In how many ways can the choreographer choose the dancers if the company has 20 dancers? 24 dancers?

10. Calculators

11. Last Example Ursula runs a small landscaping business. She has on hand 12 kinds of rose bushes, 16 kinds of small shrubs, 11 kinds of evergreen seedlings, 18 kinds of flowering lilies. In how many ways can she fill an order if a customer wants 15 varieties consisting of 4 roses, 3 scrubs, 2 evergreens, and 6 lilies?

12. Assignment Pg 279 #’s 1-10,12