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Eight chairs are numbered 1 to 8. Two women and 3 men wish to occupy one chair each. First the women choose the chairs from amongst the chairs 1 to 4 and then men select from the remaining chairs.

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Question

Eight chairs are numbered 1 to 8. Two women and 3 men wish to occupy one chair each. First the women choose the chairs from amongst the chairs 1 to 4 and then men select from the remaining chairs. Find the total number of possible arrangements.

Sum
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Solution

We have 2 women and 3 men

First women choose the chairs amongst the chairs 1 to 4

i.e. Total number of chairs = 4

So, the number of arrangements = 4P2 ways

Now 3 men choose from the remaining 6 chairs

So, the number of arrangements = 6P3 ways

∴ Total number of arrangements = 4P2 × 6P3

= `(4!)/((4 - 2)!) xx (6!)/((6 - 3)!)`

= `(4!)/(2!) xx (6!)/(3!)`

= `(4*3*2!)/(2!) xx (6*5*4*3!)/(3!)`

= 12 × 120

= 1440

Hence, the total number of possible arrangements are 1440.

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Chapter 7: Permutations and Combinations - Exercise [Page 122]

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NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 7 Permutations and Combinations
Exercise | Q 1 | Page 122

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