Enter n

Enter r

  

Evaluate the combination:

24C4

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 = 24 and r = 4

24C4  2  24!
  4!(24 - 4)!

Factorial Formula:

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

Calculate the numerator n!:

n! = 24!

24! = 24 x 23 x 22 x 21 x 20 x 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

24! = 620,448,401,733,239,409,999,872

Calculate (n - r)!:

(n - r)! = (24 - 4)!

(24 - 4)! = 20!

20! = 20 x 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

20! = 2,432,902,008,176,640,000

Calculate r!:

r! = 4!

4! = 4 x 3 x 2 x 1

4! = 24

Calculate 24C4

24C4  =  620,448,401,733,239,409,999,872
  24 x 2,432,902,008,176,640,000

24C4  =  620,448,401,733,239,409,999,872
  58,389,648,196,239,360,000

Final Answer


24C4 = 10,626