If a product is sold at 20% off the price, it can still make a profit of 20%. If it is sold at the price, how much profit can it make?
一种商品按定价的8折出售，仍可获利20%，若按定价出售可获利多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">1 / 0.8</gadget>
<output>1.25</output>

<gadget id="calculator">(6/5) * 1.25</gadget>
<output>1.5</output>

<gadget id="calculator">1.5 - 1</gadget>
<output>0.5</output>

<gadget id="calculator">0.5 / 1</gadget>
<output>0.5</output>

<result>0.5</result>