A project can be completed by team A alone in 40 days and by team B in 60 days. At the beginning, the two teams worked together, but the middle team A was transferred for a few days due to other tasks, so it took 27 days to complete the entire project. How many days did Team A leave?
一项工程，甲队单独做要40天完成，乙队单独做要60天完成．现在开始时两队合做，但中间甲队因另有任务调走几天，所以经过27天才完成全部工程．甲队离开了多少天．
<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/60) * 27</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">1 / 40</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">(11/20) / (1/40)</gadget>
<output>22</output>

<gadget id="calculator">27 - 22</gadget>
<output>5</output>

<result>5</result>