fruit shop bought a batch of apples and priced them at a profit of 40%. After selling 60% of the apples, they sold the rest at a 50% discount in order to sell them out as soon as possible. What is the profit margin earned by the store after the sale is completed.
某水果店购进一批苹果，按40%的利润定价，卖出60%后，为了尽快售完，剩下的全部打对折出售．销售完后商店获得的利润率是多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 + (2/5)</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(7/5) * (3/5)</gadget>
<output>21/25 = around 0.84</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(7/5) * (2/5) * (1/2)</gadget>
<output>7/25 = around 0.28</output>

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

<gadget id="calculator">(7/25) - 1</gadget>
<output>-18/25 = around -0.72</output>

<gadget id="calculator">(21/25) + (-18/25)</gadget>
<output>3/25 = around 0.12</output>

<result>3/25 = around 0.12</result>