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Mathematics - Permutation & Combination Question with Solution | TestHub

MathematicsPermutation & CombinationnPr & nCrEasy2 minQB

MathematicsEasysingle choice

Let $T_{n}$ denote the number of triangles which can be formed using the vertices of a regular polygon of n sides. If $T_{n + 1} - T_{n} = 21$ , then $n =$

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Answer:

Solution:

$^{(n + 1)} C_{3} -^{n} C_{3} = 21 \Rightarrow n = 7$

Stream:JEESubject:MathematicsTopic:Permutation & CombinationSubtopic:nPr & nCr

⏱ 2mℹ️ Source: QB

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