A26­7Notes.notebook
September 16, 2010
Algebra 2
Ch.6 Notes Page 21
P21 6­7 Permutations and Combinations
Aug 19­6:20 AM
Multiplication Counting Principle
If there are m ways to make a first selection and n ways to make a second selection, there are m x n ways to make the two selections.
You have 3 Pants, 5 Shirts, and 2 Jackets.
How many outfits could you wear?
How many different letter arrangements could you make with the word ROCKY?
Feb 5­2:00 PM
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A26­7Notes.notebook
September 16, 2010
Permutation Calculation
n P r
n = how many things in the group.
r = how many of the things that you are picking at a time.
Start at the number n and use the first r numbers going toward zero.
How many ways can you pick 3 people out of 8 when order is important?
5P3
You can not pick more things from the group than 5 in this example.
Feb 5­2:00 PM
Special Permutations
How many ways can you line up everything in the group?
(Not just pick a few.)
Factorial (!)
How many different ways can you line up a group of 5 things?
(When order is important.)
5! = 5x4x3x2x1 = 120
5 P 5 = 5x4x3x2x1 = 120
xPx = x! = Calculate
Example:
How many different batting orders can you have with 9 baseball players?
Feb 5­2:04 PM
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A26­7Notes.notebook
September 16, 2010
Combination Calculation
n C r
n = how many things in the group.
r = how many of the things that you are picking at a time.
Start at the number n and use the first r numbers going toward zero.
Just like a Permuation.
However, you have to divide by r! to get rid of all of the duplicates.
How many ways can you pick 3 people out of 8 when Order is Not Important?
Feb 5­2:05 PM
Graphing Calculator
Math
PRB
Option 2, 3, and 4
Sep 15­10:12 AM
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A26­7Notes.notebook
September 16, 2010
HW #18
1­6 P42 #1,6,7,10,15,17
6­7 P348 #1,2,5,6,10­13,18­24,29­32,40,46­49,56
Please put your name and class period at the top of the homework. Also include the homework number.
Aug 19­6:25 AM
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