What it means
The number of ways to choose k items from n when order does not matter. It is printed as C(n, k), ⁿCₖ or as n over k in tall brackets, and equals n! divided by k! times (n − k)!.
Read aloud in real formulas
C(5, 2) = 10
Aethel says
5 choose 2 equals 10
10 ways to choose 2 of 5
P(X = k) = C(n, k) pᵏ (1 − p)ⁿ⁻ᵏ
Aethel says
the probability that X equals k, equals n choose k, times p to the power of k, times the quantity 1 minus p, to the power of n minus k
the binomial distribution
Typing it
- LaTeX
- \binom{n}{k}
- Unicode
- —
Formulas that use it
Questions
How do you say ⁿCₖ out loud?
It is usually read “n choose k”.
What does ⁿCₖ mean in maths?
The number of ways to choose k items from n when order does not matter. It is printed as C(n, k), ⁿCₖ or as n over k in tall brackets, and equals n! divided by k! times (n − k)!.
How do you type ⁿCₖ?
In LaTeX, write \binom{n}{k}.