A project A is completed alone in 75 days. A works alone for 1 day and then B joins the project. After 2 days of cooperation, C also comes to work. Three people work together for 4 days to complete all the work (1/3), and after another 8 days, it is completed After all the work (5/6), how many days will it take for the rest C to be done alone?
一项工程甲单独75天完成，甲单独做1天后乙加入工程，合作2天后，丙也来工作，三人一起工作4天后完成全部工作的(1/3)，又过了8天，完成了全部工作的(5/6)，剩下的丙单独做要几天完成？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">(1/6) / (1/72)</gadget>
<output>12</output>

<result>12</result>