If the price of a product is increased by 10% twice in a row, and then the price is reduced by 20%, will this product make a profit or a loss? What percent has been gained or lost?
一件商品连续两次提价10%，后来又降价20%，这件商品是赚是亏？赚了或亏了百分之几？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 + (1/10)</gadget>
<output>11/10 = around 1.1</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(11/10) * (11/10) * (4/5)</gadget>
<output>121/125 = around 0.968</output>

<gadget id="calculator">1 - (121/125)</gadget>
<output>4/125 = around 0.032</output>

<result>4/125 = around 0.032</result>