It is known that car A is slower than car B. Car A and car B drive oppositely from places A and B at the same time. At a distance of 60 kilometers from the midpoint, the two cars meet for the first time, and then the two cars continue to move forward to reach B, A returns immediately after the two places. At a distance of 20 kilometers from B, the two vehicles meet for the second time. How many kilometers are there between A and B?
已知甲车比乙车慢，甲、乙两车同时从A、B两地相对开出，在距离中点60千米处，两车第1次相遇，然后两车继续前进，到达B、A两地后立即返回，在距离B地20千米处，两车第2次相遇．A、B两地相距多少千米？
<gadget id="calculator">60 * 2 * 3</gadget>
<output>360</output>

<gadget id="calculator">360 + 20 + 20</gadget>
<output>400</output>

<result>400</result>