How many planes would by formed by n non-collinear and non-coplanar points?

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- Sep 29th 2008, 05:36 AMMATHMATHmathmathMathMathProblem of the month
How many planes would by formed by n non-collinear and non-coplanar points?

- Sep 29th 2008, 09:07 AMTwistedOne151Binomial
Since three non-collinear points define a plane, this is just the number of cominations of three points we can choose from the n, which is $\displaystyle \binom{n}{3}=\frac{n!}{3!(n-3)!}=\frac{n(n-1)(n-2)}{6}$.

-Kevin C.