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In how many ways can 5 children be arranged in a line such that two particular children of them are always together

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Question

In how many ways can 5 children be arranged in a line such that two particular children of them are always together 

Sum
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Solution

We consider the arrangements by taking 2 particular children together as one and hence the remaining 4 can be arranged in 4! = 24 ways.

Again two particular children taken together can be arranged in two ways.

Therefore, there are 24 × 2 = 48 total ways of arrangement.

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Chapter 7: Permutations and Combinations - Solved Examples [Page 117]

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NCERT Exemplar Mathematics Exemplar [English] Class 11
Chapter 7 Permutations and Combinations
Solved Examples | Q 4.(i) | Page 117

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