It was originally planned that 60 people would work in 80 days to build a road. Now it took 20 days and 30 more people were added. How many days will it take to complete the remaining part?
修一条路，原计划60人工作80天完成，现在工作了20天，又增加了30人，这样剩下的部分要多少天完成？
<gadget id="calculator">20 / 80</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 / 60 / 80</gadget>
<output>1/4_800 = around 0.000208</output>

<gadget id="calculator">60 + 30</gadget>
<output>90</output>

<gadget id="calculator">(1/4_800) * 90</gadget>
<output>3/160 = around 0.01875</output>

<gadget id="calculator">(3/4) / (3/160)</gadget>
<output>40</output>

<result>40</result>