Production of a batch of parts, after innovative technology, production of the same number of parts, saving 20% of time, how much work efficiency has been improved now
生产一批零件，革新技术后，生产同样多的零件，时间节省20%，现在的工作效率提高了多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - 1</gadget>
<output>0</output>

<gadget id="calculator">(1/5) + 0</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>