15 Choose 4

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

What is 15 choose 4?

Answer

15 choose 4 is
1,365

Order doesn't matter, no repeats: 1,365 ways to choose 4 of 15 items.

C(15, 4) = 15! / (4! · 11!)

= (15 × 14 × 13 × 12) / (4 × 3 × 2 × 1)
= 32,760 / 24

= 1,365

If order matters (permutations): P(15, 4) = 15 × 14 × 13 × 12 = 32,760 — each combination in 4! = 24 orders.

Row sum: 215 = 32,768 — all subsets of 15 items.

See Also

FAQ

What is 15 choose 4?

15 choose 4 is 1,365

Why is 15 choose 4 the same as 15 choose 11?

Every way to choose 4 of 15 items leaves exactly 11 behind, so choosing 4 and choosing which 11 to leave out are the same count: 15 choose 4 = 15 choose 11 = 1,365. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(15, 4) = 32,760. Each of the 1,365 combinations can be put in order in 4! = 24 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.