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NDA 2012
Exam
NDA
Year
2012
Subject
Mathematics
Chapter
Sequences and Series

NDA 2012 · Mathematics · Sequences and Series

If 1 / 4,1 / x, 1 / 10 are in HP, then what is the value of x ?

If 1/4,1/x,1/101 / 4,1 / x, 1 / 10 are in HP, then what is the value of xx ?

Options

  1. A5
  2. B6
  3. C7
  4. D8

Correct answer

C. 7

Step-by-step solution

4,x,104, x, 10 are m AP. 2x=4+10x=142=7\begin{aligned} & 2 x=4+10 \\ & x=\frac{14}{2}=7 \end{aligned}
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