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NTA Abhyas JEE Main2020MathematicsSequences and SeriesPractice

If 5 2 5 4 5 6 … . 5 2 n = 0.04 - 28 , then the value of n is equal to

Options

  1. A7
  2. B5
  3. C6
  4. D3

Correct answer

A. 7

Step-by-step solution

The given equation can be written as 5 2 5 2 2 5 2 3 … 5 2 n = 5 2 28 5 2 1 + 2 + 3 + … + n = 5 2 28 ⇒ n n + 1 2 = 28 ⇒ n = 7

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