There is a project that Team A can complete in 40 days alone, and Team B can complete it in 60 days alone. Now the two teams are cooperating on this project, but Team A in the middle is transferred away for a few days because of other tasks, so it takes 27 days to complete all the work. , How many days does Team A leave?
有一项工程，甲队独做40天可完成，乙队独做60天可完成，现在两队合作这项工程，但中间甲队因为另有任务调走几天，所以经过27天才完成全部工作，甲队离开几天？
<gadget id="calculator">27 / 60</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">27 / 40</gadget>
<output>27/40 = around 0.675</output>

<gadget id="calculator">(27/40) - 1</gadget>
<output>-13/40 = around -0.325</output>

<gadget id="calculator">(9/20) + (-13/40)</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) / (1/40)</gadget>
<output>5</output>

<result>5</result>