9 Choose 5

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

What is 9 choose 5?

Answer

9 choose 5 is
126

Order doesn't matter, no repeats: 126 ways to choose 5 of 9 items.

Choosing 5 of 9 is the same as leaving 4 out: C(9, 5) = C(9, 4).

C(9, 5) = 9! / (5! · 4!)

= C(9, 4)

= (9 × 8 × 7 × 6) / (4 × 3 × 2 × 1)
= 3,024 / 24

= 126

If order matters (permutations): P(9, 5) = 9 × 8 × 7 × 6 × 5 = 15,120 — each combination in 5! = 120 orders.

Row 9 of Pascal's triangle
k9 choose k
01
19
236
384
4126
5126
684
736
89
91

Row sum: 29 = 512 — all subsets of 9 items.

See Also

FAQ

What is 9 choose 5?

9 choose 5 is 126

Why is 9 choose 5 the same as 9 choose 4?

Every way to choose 5 of 9 items leaves exactly 4 behind, so choosing 5 and choosing which 4 to leave out are the same count: 9 choose 5 = 9 choose 4 = 126. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(9, 5) = 15,120. Each of the 126 combinations can be put in order in 5! = 120 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.