Manufacture a batch of parts, and (1/3) of it can be completed in 18 days as planned. If the work efficiency increases (1/5) after working for 3 days, then how many days will it take to complete half of this batch of parts?
制造一批零件，按计划18天可以完成它的(1/3)．如果工作3天后，工作效率提高(1/5)，那么完成这批零件的一半，一共需要多少天．
<gadget id="calculator">1 / 54</gadget>
<output>1/54 = around 0.018519</output>

<gadget id="calculator">(1/54) * 3</gadget>
<output>1/18 = around 0.055556</output>

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

<gadget id="calculator">(1/54) * (1/5) * 3</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">(1/2) - (1/18)</gadget>
<output>4/9 = around 0.444444</output>

<gadget id="calculator">(1/18) + (1/90) + (4/9)</gadget>
<output>23/45 = around 0.511111</output>

<gadget id="calculator">(1/54) * (1/5)</gadget>
<output>1/270 = around 0.003704</output>

<gadget id="calculator">(1/54) + (1/270)</gadget>
<output>1/45 = around 0.022222</output>

<gadget id="calculator">(23/45) / (1/45)</gadget>
<output>23</output>

<result>23</result>