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Paragraph: Let P be the sum of first n positive terms of an increasing arithmetic progression A . Let Q be the sum of first n positive terms of another increasing arithmetic progression B . Let P: Q=(5 n+4):(9 n+6) Question: What is the ratio of the first term of A to that of B ?

Options

  1. A1 3
  2. B2 5
  3. C3 4
  4. D3 5

Correct answer

D. 3 5

Step-by-step solution

Given that S_n S_n^ = 5 n+4 9 n+6 Put n=1 aligned & S₁ S₁^ = 5+4 9+6 = a₁ a₁^ & a₁ a₁^ = 9 15 = 3 5 aligned

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