19 Combinations of 2 ·

10 Jul 2024, 00:00

19 Combinations of 2 Image to Crop

Evaluate the combination:

19C2

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 = 19 and r = 2

19C2 2	19!
	2!(19 - 2)!

Factorial Formula:

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

Calculate the numerator n!:

n! = 19!

19! = 19 x 18 x 17 x 16 x 15 x 14 x 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1

19! = 121,645,100,408,832,000

Calculate (n - r)!:

(n - r)! = (19 - 2)!

(19 - 2)! = 17!

17! = 17 x 16 x 15 x 14 x 13 x 12 x 11 x 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1

17! = 355,687,428,096,000

Calculate r!:

r! = 2!

2! = 2 x 1

2! = 2

Calculate 19C2

19C2 =	121,645,100,408,832,000
	2 x 355,687,428,096,000

19C2 =	121,645,100,408,832,000
	711,374,856,192,000

19C2 = 171

You have 1 free calculations remaining

Excel or Google Sheets formula:

Excel or Google Sheets formula:=COMBIN(19,2)

What is the Answer?

19C2 = 171

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?

nPr=n!/r!
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?

combinationa 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)!factorialThe product of an integer and all the integers below itpermutationa way in which a set or number of things can be ordered or arranged.
nPr = n!/(n - r)!permutations and combinations

19 Combinations of 2

Evaluate the combination: 19C2 A unique order or arrangement where n is the number of itemsr is the unique arrangements. n! = n * (n - 1) * (n - 2) * .... * 2 * 1 n! = 19! 19! = 19 x 18 x 17 x 16 x 15 x 14 x 13