The engineering team repairs a road, and repairs 20 kilometers in the first month, and repairs the full length (1/5) in the second month. At this time, the ratio of the number of kilometers that have been repaired to the number of kilometers that have not been repaired is 3:4. How many kilometers is the road?
工程队修一条公路，第一个月修了20千米，第二个月修了全长的(1/5)，这时，已修的千米数与未修的比是3：4，这条公路长多少千米？
<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/7) - (1/5)</gadget>
<output>8/35 = around 0.228571</output>

<gadget id="calculator">20 / (8/35)</gadget>
<output>175/2 = around 87.5</output>

<result>175/2 = around 87.5</result>