Question:
By selling a bouquet for Rs 322, a florist gains 15%. At what price should he sell it to gain 25%?
Solution:
SP of the bouquet = Rs 322
Gain percentage = 15%
$\mathrm{CP}$ of the bouquet $=\left(\frac{100}{100+\text { gain } \%}\right) \times \mathrm{SP}$
$=\operatorname{Rs}\left(\frac{100}{100+15}\right) \times 322$
$=\mathrm{Rs} \frac{100}{115} \times 322$
$=$ Rs 280
Now, CP = Rs 128 and desired gain percentage $=25 \%$
$\therefore$ Desired SP $=\left(\frac{100+\text { gain } \%}{100}\right) \times \mathrm{CP}$
$=$ Rs $\frac{125}{100} \times 280$
$=$ Rs 350
Hence, the selling price to obtain the desired gain must be Rs 350.