Question 366512
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No.  But the correct answer depends on whether order is significant in differentiating between selections.

If you consider the plants as being numbered 1 through 18, and that one of the selections was 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 -- <i><b>in that order</b></i> and that selection was considered different than, say, 7, 8, 9, 10, 11, 12, 1, 2, 3, 4, 5, 6, which is the same selection but in a different order, then the formula you need to use is:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ P(n,r)\ =\ \frac{n!}{(n\ -\ r)!}]


Which, for your problem becomes:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ P(18,12)\ =\ \frac{18!}{(18\ -\ 12)!}\ =\ 8,892,185,702,400]


However, if the two examples I gave (plus all other possible arrangements of the first 12) are considered the same selection, then you need another factor in your denominator:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ C(n,r)\ =\ \frac{n!}{r!(n\ -\ r)!}]


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ C(18,12)\ =\ \frac{18!}{12!(18\ -\ 12)!}\ =\ 18,564]


John
*[tex \LARGE e^{i\pi} + 1 = 0]
My calculator said it, I believe it, that settles it
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