An engineering team repairs a section of road. On the first day, it repairs the full length (1/10), and on the second day, it repairs the full length (1/8). At this time, there are 31 kilometers left to be repaired. How many kilometers is the total length of this section of road?
某工程队修一段公路，第一天修了全长的(1/10)，第二天修了全长的(1/8)，这时还剩31km没修，这段公路全长多少千米？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/10) - (1/8)</gadget>
<output>31/40 = around 0.775</output>

<gadget id="calculator">31 / (31/40)</gadget>
<output>40</output>

<result>40</result>