project alone takes 20 days, and B takes 30 days. During this period, A and B rested for a few days, but it took 16 days to complete the task. It is known that A rested for 3 days, and how many days did B rest?
一项工程，甲单独做要20天，乙要30天，其间甲乙各休息了几天，结果16天才完成任务，已知甲休息了3天，乙休息了几天？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">16 - 3</gadget>
<output>13</output>

<gadget id="calculator">(1/20) * 13</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">1 - (13/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(7/20) / (1/30)</gadget>
<output>21/2 = around 10.5</output>

<gadget id="calculator">16 - (21/2)</gadget>
<output>11/2 = around 5.5</output>

<result>11/2 = around 5.5</result>