The price of a product was increased (3/7), but it was found that the sales were not good, and the price was going to return to the original price. How much should the price be reduced?
一商品提高价格(3/7)，后来发现销售不好，准备回到原价，应该降价多少
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 + (3/7)</gadget>
<output>10/7 = around 1.428571</output>

<gadget id="calculator">(3/7) / (10/7)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>