# Permutation and Combination Calculator

Calculate the number of possible permutations and combinations for given a set of **n** elements and ** r**

All possible arrangements of a grouping of things, where the order is important is called permutation. A Grouping of things, in which the order does not matter is called Combination. Given Calculator finds the Permutation and combination of the given numbers.

Calculates the given value uing following **formula** :

Permutation:

Combination:

_{n}P_{r}= n! / (n-r)!Combination:

_{n}C_{r}=_{n}P_{r}/ r!### Example

1. Find the Permutation for Number of sample points in set n = 7 and Number of sample points r = 4.

$$ nPr = P(n,r) = \frac{n!}{(n-r)!} $$ $$ =\frac{7!}{(7-4)!}$$ $$ =\frac{7!}{(3)!} $$ $$ =\frac{5040}{6} $$ $$ =840 $$2. Find the Combination for Number of sample points in set n = 7 and Number of sample points r = 4.

$$ nPr = P(n,r) = \frac{n!}{(n-r)!} $$ $$ nCr = \frac{nPr}{r!} $$ $$ nPr =\frac{7!}{(7-4)!}$$ $$ nPr =\frac{7!}{(3)!} $$ $$ nPr =\frac{5040}{6} $$ $$ nPr =840 $$now to calculate nCr:

$$ nCr =\frac{840}{(4)!} $$ $$ nCr =\frac{840}{24} $$ $$ =35 $$