If a book is priced at 12 yuan per volume, it can make a profit of 25%. If you want to make a profit of 40%, how much should each book be priced at?
一种书如果每册定价12元，可盈利25%，如果想盈利40%，则每册定价应为多少元．
<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">12 / (5/4)</gadget>
<output>48/5 = around 9.6</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">(48/5) * (7/5)</gadget>
<output>336/25 = around 13.44</output>

<result>336/25 = around 13.44</result>