Question

By selling a book for Rs 258, a bookseller gains 20%. For how much should he sell it to gain 30%?

Answer 1

\[\text { Selling price of the book = Rs } . 258\]

\[\text { Gain % = 20 % } \]

\[\text { Since, C . P }= \left[ \frac{100}{\left( 100 +\text { Gain % } \right)} \times S . P \right]\]

\[ = \left[ \frac{100}{\left( 100 + 20 \right)} \times 258 \right]\]

\[ = \frac{25800}{120}\]

\[ = Rs . 215\]

\[\text { Let the bookseller sells it for Rs . x }\]

\[\text { So, S . P } = \left[ \frac{\left( 100 + \text { Gain % } \right)}{100} \times C . P \right]\]

\[x = \frac{100 + 30}{100} \times 215\]

\[ = \frac{130 \times 215}{100}\]

\[ = Rs . 279 . 50\]

\[\text{Therefore, the bookseller must sell the book at Rs 279 . 50 to make 30 % profit } .\]