It takes 6 hours for a passenger car to go from city A to city B, and 8 hours for a truck to go from city B to city A. Now that the two cars leave opposite each other from cities A and B at the same time, and the distance from the midpoint is 20 kilometers when they meet, then the two vehicles How many kilometers are the cities apart?
客车从甲城到乙城要6小时，货车从乙城到甲城要8小时，现两车同时从甲、乙两城相对开出，相遇时距中点20千米，则甲、乙两城相距多少千米？
<gadget id="calculator">2 * 20</gadget>
<output>40</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">40 / 1</gadget>
<output>40</output>

<gadget id="calculator">4 + 3</gadget>
<output>7</output>

<gadget id="calculator">40 * 7</gadget>
<output>280</output>

<result>280</result>