batch of processing parts. A and B work together for 1 hour to complete (11/60) of this batch of parts, then B and C work together for 1 hour to complete (1/4) of this batch of parts, and then A and C work together for 2 hours to complete For (1/5) of this batch of parts, A, B, and C will work together to complete the remaining tasks. How long will it take to complete?
一批加工零件．甲、乙两人合干1小时完成这批零件的(11/60)，接着乙、丙合干1小时完成这批零件的(1/4)，后来甲、丙又合干了2小时完成这批零件的(1/5)，剩下的任务由甲、乙、丙三人合干，问还要多少时间完成？
<gadget id="calculator">11 / 60</gadget>
<output>11/60 = around 0.183333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (11/60) - (1/4) - (1/5)</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(11/60) + (1/4) + (1/10)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">(8/15) / 2</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">(11/30) / (4/15)</gadget>
<output>11/8 = around 1.375</output>

<result>11/8 = around 1.375</result>