A store marks a book 30% above the cost. But during a sale, a 10% discount was given. If the book costs $50, what is the percent profit?
The store made a $50 x 30/100 = $
<gadget id="calculator">50*30/100</gadget>
<output>15</output>
15 profit for selling it 30% above the cost.
So, the book was sold for $50 + $15 = $
<gadget id="calculator">50+15</gadget>
<output>65</output>
65.
During a sale, the book's selling price decreased by $65 x 10/100 = $
<gadget id="calculator">65*10/100</gadget>
<output>13/2 = around 6.5</output>
6.50.
So, the book was sold for $65 - $6.50 = $
<gadget id="calculator">65-6.5</gadget>
<output>58.5</output>
58.50.
There was $58.50 - $50 = $
<gadget id="calculator">58.5-50</gadget>
<output>8.5</output>
8.50 profit after the discount.
Therefore, the percent profit is $8.50/$50 x 100% = 
<gadget id="calculator">8.5/50*100</gadget>
<output>17</output>
17%.

<result>17</result>