A product is priced at a profit of 20%, and a 10% discount is given when it is sold, so how much profit is still made for this product.
一种商品以盈利20%来定价，出售时打九折，这样这种商品仍盈利多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">90 / 100</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(6/5) * (9/10)</gadget>
<output>27/25 = around 1.08</output>

<gadget id="calculator">(27/25) - 1</gadget>
<output>2/25 = around 0.08</output>

<result>2/25 = around 0.08</result>