Two cars, A and B, start from A and B respectively at the same time. A travels 60 kilometers per hour, and B travels 40 kilometers per hour. After the first encounter, the two cars continue to move forward and reach their respective destinations. After the two places B and A, they immediately return on the original road, and the speed becomes half of their original speed. The two vehicles traveled for 6 hours from the beginning to the second encounter. How many kilometers are the distance between A and B?
甲、乙两辆汽车分别从A、B两地同时相对开出，甲每小时行60千米，乙每小时行40千米，甲、乙两辆车第一次相遇后继续前进，各自到达B、A两地后，立即按原路返回，速度变为各自原来速度的一半，两车从开始到第二次相遇共行了6小时，A、B两地相距多少千米？
<gadget id="calculator">1 + 0.5 + 0.9</gadget>
<output>2.4</output>

<gadget id="calculator">6 / 2.4</gadget>
<output>2.5</output>

<gadget id="calculator">2.5 * 60</gadget>
<output>150</output>

<result>150</result>