A project alone takes 12 days to complete, and B alone takes 14 days to complete. Now, after two people work together for a few days, A leaves for business, and the rest of the project is completed by B. In this way, B has worked on a total of 7 days, so how much did A work in total? sky?
一项工程甲单干需要12天完成，乙单干需要14天完成，现在两人合干若干天后，甲有事离开，剩余工程由乙来完成，这样乙共干了7天，那么甲共干了多少天？
<gadget id="calculator">1 / 14</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">(1/14) * 7</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/2) / (1/12)</gadget>
<output>6</output>

<result>6</result>