To do a job, A's work efficiency is equal to the sum of the work efficiency of B and C, and the ratio of C's work efficiency to the sum of A and B's work efficiency is 1:5; if three people cooperate to complete it in 10 days, How many days will it take B to complete the work alone?
做一项工作，甲的工作效率等于乙、丙二人工作效率的和，丙的工作效率与甲、乙二人工作效率的和的比是1：5；如果三人合作需10天完成，那么乙单独完成此项工作需要多少天
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) / 2</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/10) * (1/6)</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">(1/20) - (1/60)</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">1 / (1/30)</gadget>
<output>30</output>

<result>30</result>