To print a document, it takes 6 hours for A and B to print it together, 8 hours for B and C to print it together, and 12 hours for A and C to print it together. Q: If A, B, and C print together, how long will it take to complete?
打印一份资料，甲、乙两人合作打印需要6小时完成，乙、丙两人合作打印需要8小时完成，甲、丙两人合作打印需要12小时完成．问：如果甲、乙、丙三人合作打印，需要几时才能完成？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/6) + (1/8) + (1/12)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(3/8) / 2</gadget>
<output>3/16 = around 0.1875</output>

<gadget id="calculator">1 / (3/16)</gadget>
<output>16/3 = around 5.333333</output>

<result>16/3 = around 5.333333</result>