A passenger car and a truck start from A and B at the same time and drive towards each other. After 3 hours, the bus travels 35% of the whole journey, and the truck travels 40% of the whole journey. At this time, the two cars are still 180 kilometers apart. How many kilometers are there between B and B?
一辆客车和一辆货车同时从甲、乙两地出发相对而行，3小时后，客车行了全程的35%，货车行了全程的40%，这时两车还相距180千米，甲、乙两地相距多少千米？
<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (7/20) - (2/5)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">180 / (1/4)</gadget>
<output>720</output>

<result>720</result>