• # question_answer A merchant allows a discount of 10% on marked price for the cash payment. To make a profit of 17%, he must mark his goods higher than their cost price by A)  30%                 B)  33% C)  40%                 D)  27%

[a] Solving this type of question by short cut. Net profit% = $x+y+\frac{xy}{100}$ $17%=-\,10+y+\frac{(-\,10)\times y}{100}$ $[\therefore '-'for\,\,discount]$ $27=y-\,\frac{y}{10}\Rightarrow 27=\frac{10y-\,y}{10}$ $27\times 10=9y$ $x+y=100$ .Hence, He must mark his goods 30% higher than their- cost price.