The road repair team completed a section of road in three days, 30% of the total length on the first day, 2/5 of the total length on the second day, and 120 meters on the third day. How many meters is this road?
修路队三天修完一段公路，第一天修了全长30%，第二天修了全长(2/5)，第三天修了120米．这段公路长多少米？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (3/10) - (2/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">120 / (3/10)</gadget>
<output>400</output>

<result>400</result>