A road has been repaired for the full length (3/5), and there are 12 kilometers left to be repaired. How many kilometers is the total length of this road?
一条路，已修了全长的(3/5)，还剩12千米没修，这条路全长有多少千米？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">12 / (2/5)</gadget>
<output>30</output>

<result>30</result>