The master and apprentice can make a batch of parts together, and it can be completed in 6 days. If the master makes 5 days first, and the apprentice can complete this batch of parts in 8 days, how many days will it take for the apprentice to complete this batch alone?
师傅和徒弟合做一批零件，6天可以完成，如果让师傅先做5天，徒弟再做8天就可以完成这批零件，徒弟单独做完这批需要多少天？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) * 5</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">1 - (5/6)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) / 3</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 / (1/18)</gadget>
<output>18</output>

<result>18</result>