Now the cost of each piece of clothing is 20% lower than in the past, and now the cost of each piece of clothing is how much it used to be.
现在每件衣服的成本比过去降低了20%，现在每件衣服的成本是过去的多少．
<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>

<result>4/5 = around 0.8</result>