The master and the apprentice process a batch of parts at the same time. At the beginning, the two work together. After a few days, the master goes out for a meeting for 2 days, and the apprentice completes it alone. The work efficiency ratio of a person is 3:2, how many days does it take for the master to do it alone?
师徒两人同时加工一批零件，开始两人合做，若干天后师傅外出开会2天，由徒弟1个人完成，完成时师傅完成了这批零件的(1/2)，已知师徒两人的工作效率比是3：2，师傅独做用几天完成？
<gadget id="calculator">1 / 2</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">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">(1/2) - (1/3)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) / 2</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(1/12) * (3/2)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / (1/8)</gadget>
<output>8</output>

<result>8</result>