PERMUTATIONA

PERMUTATIONA(number, number_chosen)

Returns the number of permutations for a subset of objects or events (with repetition).

number	The total number of "unique" items.
number_chosen	The number of items in each permutation.

REMARKS

* A permutation is the number of possible arrangements of a set of objects when the order matters.
* If "number" is not numeric, then #VALUE! is returned.
* If "number_chosen" is not numeric, then #VALUE! is returned.
* You can use the COMBIN function to return the number of combinations for a given number of items (without repetition).
* You can use the COMBINA function to return the number of combinations for a given number of items (with repetition).
* You can use the MULTINOMIAL function to return the number of permutations for a given number of items (with duplicates).
* You can use the PERMUT function to return the number of permutations (without repetition).
* This function was added in Excel 2013.
* For the Microsoft documentation refer to support.microsoft.com

	A
1	=PERMUTATIONA(8, 3) = 512
2	=PERMUTATIONA(4, 4) = 256
3	=PERMUTATIONA(100, 1) = 100
4	=PERMUTATIONA(100, 1.9) = 100
5	=PERMUTATIONA(100, 2) = 10000
6	=PERMUTATIONA(26, 8) = 208827064576

1 - How many ways can you arrange 3 numbers from the set {1,2,3,4,5,6,7,8}
10 - How many different 8 letter passwords can be created by using all 26 letters of the alphabet.