It takes 12 days for A and B to complete a project. If A works for 3 days first, and then B works for 8 days, the total (5/12) of the work will be completed. How many days will it take if this job is done by B alone?
一项工程，甲、乙合作要12天完成，若甲先做3天后，再由乙工作8天，共完成这项工作的(5/12)．若这件工作由乙独做完需要几天？
<gadget id="calculator">5 / 12</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/12) * 3</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(5/12) - (1/4)</gadget>
<output>1/6 = around 0.166667</output>

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

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

<result>30</result>