A book in Xinhua Bookstore is priced at 15 yuan each, and after-sales can make a profit of 25%. If it is sold at 20% off the price, how much profit can it make?
新华书店一种书每本定价15元，售后可以获利25%，如果按定价八折出售可获利多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">15 * (4/5)</gadget>
<output>12</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">15 / (5/4)</gadget>
<output>12</output>

<gadget id="calculator">12 - 12</gadget>
<output>0</output>

<result>0</result>