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The fifth term of an AP of n terms, whose sum is n^2-2 n , is

Options

  1. A5
  2. B7
  3. C8
  4. D15

Correct answer

B. 7

Step-by-step solution

Given, S _ n = n ^2-2 n . We know, T _ n = S _ n - S _ n -1 So, T ₅= S ₅- S ₄ aligned & S ₅=5^2-2(5)=25-10=15 & ~S ₄=4^2-2(4)=16-8=8 aligned So. T=15-8=7 .

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