If a piece of clothing sells for 72 yuan, it will lose 20% of the money. Now, if the profit rate is 20%, how much should each piece be sold for?
一件衣服如果售价72元，就会亏本20%，现在要使利润率为20%，每件应该卖多少．
<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>

<gadget id="calculator">72 / (4/5)</gadget>
<output>90</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">90 * (6/5)</gadget>
<output>108</output>

<result>108</result>