and B work together to complete a task. If A and B work together for 2 days, B will do the rest alone, and it will be completed within the specified time; if A alone does it, it will take 18 days to complete it; if B does it alone, it will take 3 days to complete it beyond the specified time. Find the number of days required to complete the job.
甲、乙两人共同完成一件工作．如果甲、乙两人合做2天后，剩下的由乙单独做，刚好在规定时间完成；如果甲单独做需要18天完成；如果乙单独做，则要超过规定时间3天才能完成．求完成这件工作规定的天数．
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) * 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 - (1/3)</gadget>
<output>8/3 = around 2.666667</output>

<gadget id="calculator">1 - 1</gadget>
<output>0</output>

<gadget id="calculator">(1/9) + 0</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(8/3) / (1/9)</gadget>
<output>24</output>

<result>24</result>