N Choose K Calculator n=10, k=5 result

Find out how many different ways you can choose k items from a set of n items without repetition and without order. This number is also called combination number or n choose k or binomial coefficient or simply combinations. See also general combinatorial calculator.

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Calculation:

Ck​(n)=(kn​)=k!(n−k)!n!​  n=10 k=5  C5​(10)=(510​)=5!(10−5)!10!​=5⋅4⋅3⋅2⋅110⋅9⋅8⋅7⋅6​=252

The number of combinations: 252



A bit of theory - the foundation of combinatorics

Combinations

A combination of the k-th class of n elements is an unordered k-element group formed from a set of n elements. The elements are not repeated and the order does not matter. In mathematics, such unordered groups are called sets and subsets. The count is called a combination number and is calculated as follows:

Ck​(n)=(kn​)=k!(n−k)!n!​

A typical example: we have 15 students and need to choose 3. How many ways can this be done?

Foundation of combinatorics in word problems



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