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If the sequence s _n is a geometric progression and s ₂ s ₁₁= s _p ~s ₈ , then what is the value of p ?

Options

  1. A1
  2. B3
  3. C5
  4. DCan not be determined

Correct answer

C. 5

Step-by-step solution

aligned & S ₂ ~S ₁₁= S _p ~S ₈ & ( ar ) ( ar ¹⁰ )= ar ^ p-1 ( ar ^7 ) & r¹¹=r^ 7+p-1 & r¹¹=r^ 6+p & 11=6+p & p=5 aligned

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