There is a project to lay a cable line. The full length (1/4) was laid in the first week, and the full length (1/5) was laid in the second week. There are 330 kilometers left to be laid. How many kilometers long?
有一项工程要铺设一条电缆线，第一周铺设了全长的(1/4)，第二周铺设了全长的(1/5)，还剩330千米没有铺，这条电缆线全长有多少千米？
<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>

<gadget id="calculator">330 / (11/20)</gadget>
<output>600</output>

<result>600</result>