combination

Way of selecting things out of a group where order does not matter

Entitymathematical concept binary functionQ202805

Also known as choose

Instance of: mathematical concept
, binary function
Subclass of: selection

Overview

From Wikipedia, the free encyclopedia · Read full article · Text CC BY-SA 4.0

In mathematics, a combination is a selection of items from a set that has distinct members, such that the order of selection does not matter. For example, given three fruits, say an apple, an orange and a pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange. More formally, a k-combination of a set S is a subset of k distinct elements of S. So, two combinations are identical if and only if each combination has the same members. If the set has n elements, the number of k-combinations, denoted by or , is equal to the binomial coefficient:

Overview

All data

33 statements · 12% with external sources · numbers in brackets are citations

Defining formula: C^k_n = \binom nk = \frac{n(n-1)\dotsb(n-k+1)}{k(k-1)\dotsb1}
Different from: Combination
permutation
union
connection
Studied by: combinatorics
Has characteristic: number of combinations without repetition

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21 identifiers linking combination across the web's reference databases

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statements

12%

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Source last edited September 8, 2026. AIDB refreshes this page daily.

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AIDB. (2026). combination (Q202805). Retrieved from https://aidb.si/e/combination-Q202805