There are two engineering teams, A and B, participating in the construction of a certain section of the Yaxi Expressway. Team A needs 10 days to complete the construction alone, and team B needs 15 days to complete the construction alone. Team A and Team B worked together for 2 days, and Team B completed the rest of the project alone. How many days did this project take?
有甲﹑乙两个工程队参与雅西高速某段公路的修建，甲队单独施工需要10天完成，乙队单独施工需要15天完成．甲﹑乙两队合作2天后，剩下的工程由乙队单独完成，则这项工程共用了多少天？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 2</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">(2/3) / (1/15)</gadget>
<output>10</output>

<gadget id="calculator">10 + 2</gadget>
<output>12</output>

<result>12</result>