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KCET2022MathematicsSequences and Series

If a₁, a₂ ; a₃, , a₁₀ is a geometric progression and a₃ a₁ =25 , then a₉ a₅ equals

Options

  1. A3 (5^2 )
  2. B5^4
  3. C5^3
  4. D2 (5^2 )

Correct answer

B. 5^4

Step-by-step solution

Given, GP : a₁, a₂, a₃, , a₁₀ and a₃ a₁ =25 a r^2 a =25 r^2=25 Now, a₉ a₅ = a r^8 a r^4 =r^4 = (r^2 )^2=(25)^2=5^4

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