Permutations

Permutations are Lists, given arrangement is redefined in how many ways that is permutation.



Have look at the following examples.



Consider the word : Traingle



in this word number of characters are : 8



8! = 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 40320.



Another example:



Consider the word: Remember



in this word number of characters are : 8.



but here repetitive characters are 3.



Those are  R - 2 times

                 E - 3 times

                 M -2 times



so 8! / (2! x 3! x 2!) = 1680.



By observing above two examples first word does not have repetitive characters but in the second word three (3) characters are repetitive.