11 Choose 11

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

What is 11 choose 11?

Answer

11 choose 11 is
1

Order doesn't matter, no repeats: 1 way to choose 11 of 11 items.

There is exactly one way: take all.

C(11, 11) = 11! / (11! · 0!)

= 1

0! = 1 (an empty product), so 11! cancels out completely.

If order matters (permutations): P(11, 11) = 11 × 10 × 9 × … × 1 = 39,916,800 — each combination in 11! = 39,916,800 orders.

Row 11 of Pascal's triangle
k11 choose k
01
111
255
3165
4330
5462
6462
7330
8165
955
1011
111

Row sum: 211 = 2,048 — all subsets of 11 items.

See Also

FAQ

What is 11 choose 11?

11 choose 11 is 1

Why is 11 choose 11 the same as 11 choose 0?

Every way to choose 11 of 11 items leaves exactly 0 behind, so choosing 11 and choosing which 0 to leave out are the same count: 11 choose 11 = 11 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(11, 11) = 39,916,800. The only combination — all 11 items — can be put in order in 11! = 39,916,800 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.