A project can be completed in 2 days (1/9) by A alone, and 12 days by B alone. If A works alone after 3 days, B will continue to do the rest. How many days will it take to complete the project?
一件工程，甲独做2天完成(1/9)，乙独做12天完成，如果甲独做3天后，余下的由乙接着做，完成这项工程共需多少天？
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) / 2</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(1/18) * 3</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 - (1/6)</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(5/6) / (1/12)</gadget>
<output>10</output>

<gadget id="calculator">10 + 3</gadget>
<output>13</output>

<result>13</result>