In order to complete a project 20 days ahead of schedule, it is necessary to increase the original work efficiency by 25%, how many days will it take to complete the project originally planned.
为使某工程提前20天完成任务，需将原定工作效率提高25%，则原计划完成这项工程需要多少天．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * 20</gadget>
<output>5</output>

<gadget id="calculator">20 + 5</gadget>
<output>25</output>

<gadget id="calculator">(1/4) - 1</gadget>
<output>-3/4 = around -0.75</output>

<gadget id="calculator">1 + (-3/4)</gadget>
<output>1/4 = around 0.25</output>

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

<result>100</result>