A job, 5 days to complete it (1/4). Calculate how many days it will take to complete all the work in this way.
一件工作，5天完成它的(1/4)．照这样计算完成全部工作要多少天天．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 5</gadget>
<output>1/20 = around 0.05</output>

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

<result>20</result>