After allowing a discount of 10% on the marked price, a trader still makes a gain of 17%.

Solution:

Let $R s 100$ be the cost price.

Gain required = $17 \%$

$\therefore$ Selling price $=R s 117$

Let the marked price be $R s x$.

Then, discount $=10 \%$ of $\mathrm{x}$

$=\frac{10}{100} \times x$

$=\frac{x}{10}$

Selling Price = MP − discount

$\Rightarrow 117=x-\frac{x}{10}$

$\Rightarrow 117=\frac{9 x}{10}$

$\Rightarrow 9 x=1170$

$\Rightarrow x=\frac{1170}{9}$

$\Rightarrow x=130$

$\therefore$ Marked price $=R s 130$

Hence, the marked price is $30 \%$ above the cost price.