A batch of goods has 1,000 tons, 20% of the first shipment, and 25% of the second shipment, how much of the remaining goods account for this batch of goods.
一批货物有1000吨，第一次运走20%，第二次运25%，剩下的货物占这批货物的多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/5) - (1/4)</gadget>
<output>11/20 = around 0.55</output>

<result>11/20 = around 0.55</result>