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Combinations

Before we go on to the next section, let's just mess with out "choose" formula for awhile...

Let's crunch these out:

( 5 3 ) = 5! / ( 5 - 0 )! 0! = 5! / 5! 0! = 1 ... Remember... 0! = 1
Does this make sense?  Think about it...

How many ways can you choose 0 things from 5 things?

One way -- you just sit there and do nothing!


( 0 0 ) = 0! / ( 0 - 0 )! 0! = 0! / 0! 0! = 1
How many ways can you choose 0 things from 0 things?

 

( 6 1 ) = 6! / ( 6 - 1 )! 1! = 6! / 5! 1! = 6 * 5! / 5! 1! = 6
How many ways can you choose 1 thing from 6 things?