A project, originally planned to be completed in 25 days, actually only took 20 days, how much the work efficiency will be improved.
一项工程，原计划要25天完成，实际只用了20天，则工作的效率提高多少．
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 25</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">(1/20) - (1/25)</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">(1/100) / (1/25)</gadget>
<output>1/4 = around 0.25</output>

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