To type a manuscript, A alone typed, and it took 6 hours to complete. If you play in the order that A, B, and C take turns playing for 1 hour each, it will be completed in full hours; It will take 0.5 hours more to complete the playing in the order of C taking turns; if playing in the order of C, A, and B each playing for 1 hour in turn, it will take 0.25 hours more to complete than playing in the order of A, B, and C in turn. Now A, B, and C will type this manuscript together. How many hours will it take to complete?
打一份稿件，甲单独打，要6小时完成．如果按甲、乙、丙轮流每人打1小时的顺序去打，正好用整小时数完成；如果按乙、丙、甲轮流每人打1小时的顺序去打，就要比甲、乙、丙轮流的顺序去打多用0.5小时完成；如果按丙、甲、乙轮流每人打1小时的顺序去打，就要比按甲、乙、丙轮流的顺序去打多用0.25小时完成．现在由甲、乙、丙合打这份稿件，需要几小时完成？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">1 + (2/3) + (1/2)</gadget>
<output>13/6 = around 2.166667</output>

<gadget id="calculator">6 / (13/6)</gadget>
<output>36/13 = around 2.769231</output>

<result>36/13 = around 2.769231</result>