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An Amazing Series

Algebra Level 2

\(S=1+2+3+\cdots+(n-1)+n+(n-1)+\ldots+3+2+1\)

Find general formula of \(S\).

\[2{n}^{2}\] \[{n}^{2}\] \[2n\] \[{\left(\dfrac{n}{2}\right)}^{2}\]

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by Dinesh Nath Goswami

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