Two people, A and B, start from A and B at the same time and walk towards each other, but A's speed is faster than B's. The two meet for the first time at a place 240 meters away from point B. Returning at the original speed, the second encounter is at a place 120 meters away from A, how many meters are the distance between A and B?
甲、乙两人同时从A、B两地出发相向而行，而甲速快于乙速，两人第一次相遇在距B点240米的地方，两人分别到达B、A后又立即以原速返回，第二次相遇在距A地120米的地方，求A、B两地相距多少米？
<gadget id="calculator">240 * 3</gadget>
<output>720</output>

<gadget id="calculator">720 - 120</gadget>
<output>600</output>

<result>600</result>