A project can be completed in 30 days by A alone, and 24 days by B alone. If A works for 5 days first, and B does the rest alone, it will take a few more days.
一项工程，甲单干30天完成，乙单干24天完成，如果甲先干5天，剩下的由乙单干，还要几天．
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/30) * 5</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">(5/6) / (1/24)</gadget>
<output>20</output>

<result>20</result>