मराठी

Suppose m men and n women are to be seated in a row so that no two women sit together. If m > n, show that the number of ways in which they can be seated is mmmnm!(m+1)!(m-n+1)1

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प्रश्न

Suppose m men and n women are to be seated in a row so that no two women sit together. If m > n, show that the number of ways in which they can be seated is `(m!(m + 1)!)/((m - n + 1)1)`

बेरीज
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उत्तर

Let the men take their seats first.

They can be seated in mPm ways as shown in the following figure

From the above figure, we observe, that there are (m + 1) places for n women.

It is given that m > n and no two women can sit together.

Therefore, n women can take their seats (m+1)Pn ways

And hence the total number of ways so that no two women sit together is

`(""^nP_m) xx (""^(m + 1)P_n) = (m!(m + 1)!)/((m - n + 1)1)`

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पाठ 7: Permutations and Combinations - Solved Examples [पृष्ठ ११८]

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एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
पाठ 7 Permutations and Combinations
Solved Examples | Q 8 | पृष्ठ ११८

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