A commodity is priced at a profit of 30%. When 70% of the commodities are sold, the store decides to sell the rest at 20% off the price. When the batch of stores is sold out, what is the actual profit margin for the store?
某种商品按30%的利润来定价，当售出这批商品的70%后，商店决定把剩下的按定价的八折出售．当这批商店销售完后，商店的实际利润率是多少？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 + (3/10)</gadget>
<output>13/10 = around 1.3</output>

<gadget id="calculator">70 / 100</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 * (13/10) * (7/10)</gadget>
<output>91/100 = around 0.91</output>

<gadget id="calculator">80 / 100</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1.3 * (4/5) * (3/10)</gadget>
<output>0.312</output>

<gadget id="calculator">0.312 - 1</gadget>
<output>-0.688</output>

<gadget id="calculator">(91/100) + (-0.688)</gadget>
<output>0.222</output>

<gadget id="calculator">0.222 / 1</gadget>
<output>0.222</output>

<result>0.222</result>