and B work together on one job, and if they can finish all the work every day (1/12), A will do it alone for 6 days, and B will do it alone for 10 days, and if there is still all the work to be done (11/30), A will finish all the work alone How many days will it take?
甲、乙合作一件工作，每天能完成全部工作的(1/12)，甲单独做6天，乙单独做10天后，还剩全部工作的(11/30)没有完成，甲单独完成全部工作需要多少天？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">11 / 30</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">(1/12) * 6</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (11/30) - (1/2)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(2/15) / 4</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/12) - (1/30)</gadget>
<output>1/20 = around 0.05</output>

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

<result>20</result>