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Question
In the permutations of n things, r taken together, the number of permutations in which m particular things occur together is `""^(n - m)"P"_(r - m) xx ""^r"P"_m`.
Options
True
False
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Solution
This statement is False.
Explanation:
Arrangement of n things, r taken at a time in which m things occur together.
So, number of object excluding m object = (r – m)
Here, we first arrange (r – m + 1) object
∴ Number of arrangements = (r – m + 1)!
m objects can be arranged in m! ways
So, the required number of arrangements = (r – m + 1)! × m!
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