The price of a product is reduced by 20% first, and then sold at a 30% discount for promotion. What percentage is the price after the discount before the two price reductions?
一种商品先降价20%，为了促销，又打七折销售，打折后的价格是两次降价前的百分之几？
<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">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">(4/5) * (7/10)</gadget>
<output>14/25 = around 0.56</output>

<result>14/25 = around 0.56</result>