Question:
Mark (✓) against the correct answer
The selling price of an article is $\frac{6}{5}$ of the cost price. The gain per cent is
(a) 15%
(b) 20%
(c) 25%
(d) 30%
Solution:
(b) 20%
Let $x$ be the CP of the article.
Then, SP of the article $=\frac{6}{5} x$
Now, gain $=(\mathrm{SP}-\mathrm{CP})$
$=\left(\frac{6}{5} \mathrm{x}-\mathrm{x}\right)$
$=\frac{\mathrm{x}}{5}$
$\therefore$ Gain percentage $=\left(\frac{\text { gain }}{\mathrm{CP}} \times 100\right) \%$
$=\left(\frac{\frac{x}{5}}{x} \times 100\right) \%$
$=\left(\left(\frac{x}{5} \times \frac{1}{x}\right) \times 100\right) \%$
$=20 \%$