A and B cooperate to complete a task in 8 days, and B and C cooperate in 9 days. C and A work together to complete the work in 18 days. If C does it alone, how many days will it take to complete the work?
一项工作，甲、乙两人合作8天完成，乙、丙两人合作9天完成．丙、甲两人合作18天完成，那么丙一个人来做，完成这项工作需要多少天？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(1/8) + (1/9) + (1/18)</gadget>
<output>7/24 = around 0.291667</output>

<gadget id="calculator">(7/24) / 2</gadget>
<output>7/48 = around 0.145833</output>

<gadget id="calculator">(7/48) - (1/8)</gadget>
<output>1/48 = around 0.020833</output>

<gadget id="calculator">1 / (1/48)</gadget>
<output>48</output>

<result>48</result>