Meenakshi sells a pen for Rs 54 and loses

SP of the pen $=$ Rs. 54

Let Rs $x$ be the CP of the pen.

Loss $=$ Rs. $\frac{x}{10}$

$\mathrm{SP}=\mathrm{CP}-$ Loss

$=x-\frac{x}{10}$

$=$ Rs. $\frac{9 x}{10}$

Now, we have $\frac{9 \mathrm{x}}{10}=54$

$\Rightarrow x=54 \times \frac{10}{9}$

$\Rightarrow \mathrm{x}=60$

$\therefore$ CP of the pen $=$ Rs. 60

Now, loss $=\frac{\mathrm{x}}{10}$

Now, loss $=\frac{x}{10}$

$=\frac{60}{10}$

$=\operatorname{Rs} .6$

$\therefore$ Loss percentage $=\left(\frac{\text { loss }}{\mathrm{CP}} \times 100\right) \%$

$=\left(\frac{6}{60} \times 100\right) \%$

$=10 \%$