 # 8 Combinations of 3

## Enter your n and r values below:

<-- Enter (n)
<-- Enter (r)

Evaluate the combination:
8C3

## Combination Definition:

A unique order or arrangement

## Combination Formula:

 nCr  = n! r!(n - r)!

where n is the number of items
r is the unique arrangements.

## Plug in n = 8 and r = 3

 8C3  2 8! 3!(8 - 3)!

## Factorial Formula:

n! = n * (n - 1) * (n - 2) * .... * 2 * 1

## Calculate the numerator n!:

n! = 8!
8! = 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1
8! = 40,320

## Calculate (n - r)!:

(n - r)! = (8 - 3)!
(8 - 3)! = 5!
5! = 5 x 4 x 3 x 2 x 1
5! = 120

r! = 3!
3! = 3 x 2 x 1
3! = 6

## Calculate 8C3

 8C3  = 40,320 6 x 120

 8C3  = 40,320 720

## Excel or Google Sheets formula:

=COMBIN(8,3)

8C3 = 56

### How does the Permutations and Combinations Calculator work?

Free Permutations and Combinations Calculator - Calculates the following:
Number of permutation(s) of n items arranged in r ways = nPr
Number of combination(s) of n items arranged in r unique ways = nCr including subsets of sets
This calculator has 2 inputs.

### What 2 formulas are used for the Permutations and Combinations Calculator?

1. nPr=n!/r!
2. nCr=n!/r!(n-r)!

For more math formulas, check out our Formula Dossier

### What 4 concepts are covered in the Permutations and Combinations Calculator?

combination
a mathematical technique that determines the number of possible arrangements in a collection of items where the order of the selection does not matter
nPr = n!/r!(n - r)!
factorial
The product of an integer and all the integers below it
permutation
a way in which a set or number of things can be ordered or arranged.
nPr = n!/(n - r)!
permutations and combinations