40% of a road has been repaired, and there are still 42 kilometers left to be repaired. How long is this road in kilometers?
一条公路，已修了40%，还剩下42千米没有修．这条公路全长多少千米？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">42 / (3/5)</gadget>
<output>70</output>

<result>70</result>