To process a batch of parts, A alone needs 8 hours, B alone takes 7 hours, and C alone takes 14 hours to complete. After three people cooperate for 2 hours, A leaves because of other business, and B and C continue to cooperate. Hours to complete?
加工一批零件，甲单独做需要8小时，乙单独做需要7小时，丙单独做需要14小时才能完成，三人合作2小时后，甲因另外有事离开，乙丙两人继续合作还需要几小时才能完成？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / 14</gadget>
<output>1/14 = around 0.071429</output>

<gadget id="calculator">(1/8) + (1/7) + (1/14)</gadget>
<output>19/56 = around 0.339286</output>

<gadget id="calculator">(19/56) * 2</gadget>
<output>19/28 = around 0.678571</output>

<gadget id="calculator">1 - (19/28)</gadget>
<output>9/28 = around 0.321429</output>

<gadget id="calculator">(1/7) + (1/14)</gadget>
<output>3/14 = around 0.214286</output>

<gadget id="calculator">(9/28) / (3/14)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>