Question:
A tradesman marks his goods at such a price that after allowing a discount of 15%, he makes a profit of 20%. What is the marked price of an article whose cost price is Rs 170?
Solution:
Given,
CP of the article $=R s .170$
Profit $=20 \%$
We know that,
$\mathrm{SP}=\left[\frac{(100+\text { Gain } \%)}{100} \times \mathrm{CP}\right]$
$=\left[\frac{120}{100} \times 170\right]$
$=\frac{20400}{100}$
$=$ Rs. 204
Let the MP of the article be Rs. $x$.
Discount $=15 \%$
There fore, Discount $=15 \%$ of $x$
$=0.15 x$
So, SP $=$ MP $-$ Discount
MP $=$ SP + Discount
$x=204+0.15 x$
$x-0.15 x=204$
$0.85 x=204$
$x=$ Rs. 240
Thus, the marked $p$ rice of the article is Rs. 240 .