A man sells a bicycle at marked price which is 30% higher than the cost price. If he gives some discount and sells it at Rs. 150 less than the marked price, he would still gain 20%. What is the percentage of discount offered ?

Solution (By Examveda Team)

\[\begin{gathered} {\text{30}}\% = \frac{{{3^{{ \nearrow ^{{\text{gain}}}}}}}}{{{\text{ }}{{10}_{{ \searrow _{{\text{cost price}}}}}}}}{\text{marked price}} = 13{\text{ }} \hfill \\ {\text{20}}\% = \frac{{{1^{{ \nearrow ^{{\text{profit}}}}}}}}{{{\text{ }}{5_{{ \searrow _{{\text{cost price}}}}}}}}{\text{selling price}} = 6{\text{ }} \hfill \\ \end{gathered} \]

\[\begin{gathered} \begin{array}{*{20}{c}} {{\text{Cost price}}}&{{\text{Selling price}}}&{{\text{Marked price}}} \\ {10}&{}&{13} \\ {5 \times 2}&{6 \times 2}&{} \end{array} \hfill \\ {\text{ }}\overline {\,\,\,10{\text{ units}}\,\,\,\,\,\,\,\,\,\,\,\underbrace {12\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,1{\text{3 unit}}}_{{\text{discount = 1}}}} \hfill \\ \end{gathered} \]

$$\eqalign{ & \therefore {\text{Discount }}\% \cr & = \frac{1}{{13}} \times 100 \cr & = 7.69\% \cr} $$