Question

If $R$ be the harmonic mean between $H$ and $Q$, then the value of $\frac{R}{H}+\frac{R}{Q}$ is

• A. $\frac{HQ}{H+Q}$
• B. $\frac{H+Q}{HQ}$
• C. $2$
• D. $R^2$

Answer 1

Answer: (C)

$2$

Given R is harmonic mean of H and Q
$\Rightarrow$ R $=$ $\frac{2HQ}{H+Q}$
Now, $\frac{R}{H}$ + $\frac{R}{Q}$ $=$ $R(\frac{H+Q}{HQ}$) $=$ $R(\frac{2}{R}$) $=$ 2.
Hence, option 'B' is correct.