A project can be completed by A alone in 24 days and by B in 20 days. Now the cooperation between A and B is completed after 16 days. It is known that A has rested for 4 days during this period, so B has rested for a few days.
一项工程，甲单独做了24天完成，乙独做20天完成．现在甲、乙合作经过16天完成，已知在这段时间内甲休息了4天，那么乙休息了几天．
<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">16 - 4</gadget>
<output>12</output>

<gadget id="calculator">(1/24) * 12</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/2) / (1/20)</gadget>
<output>10</output>

<gadget id="calculator">16 - 10</gadget>
<output>6</output>

<result>6</result>