Cars A and B set off from places A and B at the same time, and drive towards each other at a constant speed. When they meet for the first time, they are 150 kilometers away from place A. The two vehicles continue to move forward separately, and return immediately after arriving at places B and A respectively without stopping, and meet for the second time at a place 70 kilometers away from A. What is the distance in miles between A and B?
甲、乙两车分别从A、B两地同时出发，匀速相向而行，第一次相遇时离A地150千米．两车继续各自前行，分别到达B、A两地后立即返回，不作停留，在离A地70千米处第二次相遇．A、B两地间的距离为多少千米．
<gadget id="calculator">150 * 3</gadget>
<output>450</output>

<gadget id="calculator">450 + 70</gadget>
<output>520</output>

<gadget id="calculator">520 / 2</gadget>
<output>260</output>

<result>260</result>