The master and the apprentice worked together for 6 days (2/5), and then the apprentice worked for another 6 days, leaving (13/30). It is known that after the cooperation, the master's work efficiency improved (1/10), and the apprentice improved (1/30) 5), so how many days does the master complete the work?
师徒两人工作，6天干了(2/5)，后来徒弟又干了6天，还剩(13/30)，已知合作后，师傅工效提高(1/10)，徒弟提高(1/5)，那么师傅一人多少天完成这项工作？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">5 / 33</gadget>
<output>5/33 = around 0.151515</output>

<gadget id="calculator">(1/5) * (5/33)</gadget>
<output>1/33 = around 0.030303</output>

<gadget id="calculator">1 / (1/33)</gadget>
<output>33</output>

<result>33</result>