To build a road, the full length (3/10) was repaired in the first month, and 35% of the total length was repaired in the second month, leaving 168 kilometers. How many kilometers is the total length of this road?
修一段公路，第一个月修了全长的(3/10)，第二个月修了全长的35%，还剩168千米，这条公路全长多少千米？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">1 - (3/10) - (7/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">168 / (7/20)</gadget>
<output>480</output>

<result>480</result>