Most recent change of Combination

Edit made on June 22, 2013 by ColinWright at 17:55:07

Deleted text in red / Inserted text in green

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HEADERS_END
A Combination is an unordered subset of a set.

For example, the 10 possible combinations of 3 letters from the set of vowel vowels { A, E, I, O, U } are:

AEI, AEO, AEU, AIO, AIU, AOU, EIO, EIU, EOU and IOU.

Order does not matter so the choice AEI and EAI are considered the same.

[[[>50 The use of the word Combination "Combination" with reference to combination locks
is incorrect as the code is really actually a permutation. permutation - the order matters. ]]]
Order does not matter, so the choices "AEI" and "EAI" (for example) are considered to be the same.


The calculation of the number of combinations makes use of the factorial notation,
binomial coefficients and Pascal's triangle.