Can someone explain the basic difference between permutation and combination?

Are there a formula(s) to know?

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- Sep 28th 2008, 07:03 AMmagentaritaPermutation and Combination
Can someone explain the basic difference between permutation and combination?

Are there a formula(s) to know?

- Sep 28th 2008, 07:34 AMPlato
Permutations are order driven: the number of ways to form a queue.

Combinations are content driven: the number of ways to form a collection.

$\displaystyle P\left( {N,k} \right) = \frac{{N!}}{{\left( {N - k} \right)!}} = N(N - 1)(N - 2) \cdots (N - k + 1)$

$\displaystyle C(N,k) = {{N} \choose {k}}= \frac{{N!}}{{k!\left( {N - k} \right)!}}$ - Sep 28th 2008, 09:37 PMmagentaritagreat notes