16 Choose 4

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Total items (n)
Items chosen (k)

What is 16 choose 4?

Answer

16 choose 4 is
1,820

Order doesn't matter, no repeats: 1,820 ways to choose 4 of 16 items.

C(16, 4) = 16! / (4! · 12!)

= (16 × 15 × 14 × 13) / (4 × 3 × 2 × 1)
= 43,680 / 24

= 1,820

If order matters (permutations): P(16, 4) = 16 × 15 × 14 × 13 = 43,680 — each combination in 4! = 24 orders.

Row sum: 216 = 65,536 — all subsets of 16 items.

See Also

FAQ

What is 16 choose 4?

16 choose 4 is 1,820

Why is 16 choose 4 the same as 16 choose 12?

Every way to choose 4 of 16 items leaves exactly 12 behind, so choosing 4 and choosing which 12 to leave out are the same count: 16 choose 4 = 16 choose 12 = 1,820. In the formula n! / (k! (n − k)!) the two factorials below just swap places.

How many ways are there if order matters?

P(16, 4) = 43,680. Each of the 1,820 combinations can be put in order in 4! = 24 ways, so permutations = combinations × k!: P(n, k) = n! / (n − k)!.