Answer:
[tex]P(n,r) = \dfrac{n!}{(n-r)!}[/tex]
Step-by-step explanation:
We have to fill the blank.
The number of permutations of n elements taken r at a time is given by the formula:
[tex]P(n,r) =^nP_r = \dfrac{n!}{(n-r)!}[/tex]
Permutation is an arrangement of subsets of a larger set in regard with order of the arrangement.
where n is the the larger set and we have to choose r items from n such that there is no repetition.
In permutation, order is important.