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BITSAT 2011
Exam
BITSAT
Year
2011
Subject
Mathematics
Chapter
Sequences and Series

BITSAT 2011 · Mathematics · Sequences and Series

If the sum of the first 2 n terms of (2,5,8, ) is equal to the sum...

If the sum of the first 2n2 n terms of (2,5,8, \ldots \ldots) is equal to the sum of the first nn terms of 57,59 , (61 \ldots \ldots). , then (n\mathrm{n}) is equal to

Options

  1. A10
  2. B12
  3. C11
  4. D13

Correct answer

C. 11

Step-by-step solution

Given, (2n2\frac{2 n}{2}\{2.2+(2 n-1) 3\}=n2\frac{n}{2}\{2.57+(n-1) 2\}) or 2(6n+1)=112+2n2(6 n+1)=112+2 n or (10 n=110, ~\therefore n=11)
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