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JEE MATHEMATICS MCQ: PERMUTATIONS

1 Easy

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Application +4 | -1

Given that

\mathrm{n}

is odd, the number of ways in which three numbers in A.P. can be selected from

1,2,3, \ldots . \mathrm{n}

is

View answer and explanation

Correct option: D

\frac{(\mathrm{n}-1)^2}{4}

Option D (

\frac{{(n-1)^2}}{{4}}

) is correct because it accounts for selecting two even or two odd numbers from the set to form an arithmetic progression.

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