If a product is sold at a 20% discount, a 20% profit can still be obtained. What is the expected profit when pricing.
某商品打八折出售，仍能获得20%的利润，定价时期望的利润是多少．
<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<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">(4/5) / (6/5)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 * (2/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) / (2/3)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>