There are 5 tons of goods to be transported. Vehicle A has already transported (1/4) of this batch of goods, and vehicle B has already transported (1/5) of this batch of goods. What percentage of this batch of goods is left undelivered?
有5吨货物需要运送，甲车已经运了这批货物的(1/4)，乙车已经运了这批货物的(1/5)，还剩这批货物的几分之几没有运？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

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

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