It takes 18 days for two engineering teams, A and B, to complete a project. If team A works in 3 days and team B completes the project in 4 days (1/5), then how many days will it take for team B to complete the project independently?
甲、乙两个工程队共同完成一项工程需18天，如果甲队干3天，乙队干4天完成工程的(1/5)，那么乙队独立完成该工程需多少天．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 18</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/5) - (1/6)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>