For one project, Team A will complete it in 12 days alone, Team B will work alone in 15 days, and Team C will complete 1/5 of the entire project in 2 days. How many days will it take to complete?
一件工程，甲队单独做12天完成，乙队单独做15天，丙队2天完成全部工成的(1/5)，甲乙两队合做2天后，剩下的工程由丙队独做，还要多少天完成？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

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

<gadget id="calculator">(1/12) + (1/15)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 2</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) / 2</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(7/10) / (1/10)</gadget>
<output>7</output>

<result>7</result>