project can be completed by A alone in 12 hours, B alone in 12 hours, C alone in 15 hours, A and B work together for 2 hours, and C alone will complete the rest. How many hours will it take?
一项工程，甲单独做12小时完成，乙单独做12小时完成，丙单独做15小时完成，甲、乙合做2小时后，剩下的由丙单独完成，还需几小时才能完成？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/12) + (1/12)</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">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

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

<result>10</result>