To build a road, 15% is completed on the first day, and 20% is completed on the second day, which is 50 meters more than the first day. What is the total length of this road in meters?
修一条公路，第一天完成15%，第二天完成20%，比第一天多完成50米，这条公路总长为多少米．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(1/5) - (3/20)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">50 / (1/20)</gadget>
<output>1_000</output>

<result>1_000</result>