A project needs 10 days to be done by A alone, 12 days to be done by B alone, and 15 days to be done by C alone. Now A, B, and C are working together for 2 days. C has completed the cooperation. How many days will it take to complete the project?
一项工程，甲独做需要10天，乙独做需要12天，丙独做需要15天，现甲，乙，丙3人合做2天后，乙因有事提前离去，余下的由甲和丙合作完成，问还需几天能完成这项工程？
<gadget id="calculator">19 / 60</gadget>
<output>19/60 = around 0.316667</output>

<gadget id="calculator">(19/60) * 2</gadget>
<output>19/30 = around 0.633333</output>

<gadget id="calculator">1 - (19/30)</gadget>
<output>11/30 = around 0.366667</output>

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

<gadget id="calculator">(11/30) / (1/6)</gadget>
<output>11/5 = around 2.2</output>

<result>11/5 = around 2.2</result>