10 Choose 10

Combination Calculator
Total items (n)
Items chosen (k)

What is 10 choose 10?

Answer

10 choose 10 is
1

Order doesn't matter, no repeats: 1 way to choose 10 of 10 items.

There is exactly one way: take all.

C(10, 10) = 10! / (10! · 0!)

= 1

0! = 1 (an empty product), so 10! cancels out completely.

If order matters (permutations): P(10, 10) = 10 × 9 × 8 × … × 1 = 3,628,800 — each combination in 10! = 3,628,800 orders.

Row 10 of Pascal's triangle
k10 choose k
01
110
245
3120
4210
5252
6210
7120
845
910
101

Row sum: 210 = 1,024 — all subsets of 10 items.

See Also

FAQ

What is 10 choose 10?

10 choose 10 is 1

Why is 10 choose 10 the same as 10 choose 0?

Every way to choose 10 of 10 items leaves exactly 0 behind, so choosing 10 and choosing which 0 to leave out are the same count: 10 choose 10 = 10 choose 0 = 1. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(10, 10) = 3,628,800. The only combination — all 10 items — can be put in order in 10! = 3,628,800 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.