Factorial

Multiply a number by all whole numbers between it and 1.

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How Many Ways to Arange 5 Cards

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​That means that the number of ways is:

A permutation is a mathematical calculation of the number of ways a particular set can be arranged, where the order of the arrangement matters

Definition:

How many was are there to arange r things out of n things?

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The number of ways to arange things​

Permutations

​ We have 27 and are arranging 3

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Permutations

Calculator

Directions​

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1. Type in the n value

2. Press MATH

3. Move over to PRB​

4. Select nPr

5. Type in rthe r value

Example

Given a class of 15 students and a front row of 5 seats, how many different ways could students be arranged in the front row assuming all seats are filled?

This is a permutation

Combinations

How many ways to select r objects from n objects:

Smaller than nPr (we are dividing by r!)

1. ​Type in the value of n

2. Press MATH

3. Move over to PRB or PROB

4. ​Move down to nCr or press 3

5. ​Type in the value of r

6. Press enter​

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Calculator

Example:

How many different 5 hard hands are there for a 52 card deck?

Some More Problems

See if you can get these​