After A works alone for 6 days, B works alone for another 5 days, leaving (1/6) of the project. It is known that B alone needs 30 days to complete this project, how many days does A need to do this project alone?
一件工程甲独做6天后，乙又独做5天，还剩下这件工程的(1/6)．已知乙独做需要30天才能完成这件工程，请问甲独做这件工程需要多少天？
<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/30) * 5</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6) - (1/6)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">6 / (2/3)</gadget>
<output>9</output>

<result>9</result>