Two cars, A and B, drive from places A and B at different speeds at the same time. They meet for the first time at a distance of 90 kilometers from place A. They return immediately after arriving at their destinations. Meet at 30 kilometers. How many miles is the distance between A and B?
甲、乙两辆汽车分别以不同的速度同时从A、B两地相对开出，第一次在离A地90千米处相遇，各自到达目的地后立即返回，第二次在离B地30千米处相遇．AB两地相距多少千米？
<gadget id="calculator">90 * 3</gadget>
<output>270</output>

<gadget id="calculator">270 - 30</gadget>
<output>240</output>

<result>240</result>