After a 20% discount, "Five Thousand Years of China" is now 300 yuan per set, how much was each set originally.
《中华上下五千年》打了八折后现在每套300元，原来每套多少元．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">300 / (4/5)</gadget>
<output>375</output>

<result>375</result>