Cars A and B leave opposite directions at the same time from stations A and B. After meeting at a place 60 kilometers away from station A, the two cars continue to move forward at the original speed. Meet at a place 30 kilometers away from station B. Question: How many kilometers are there between stations A and B?
甲、乙两车同时从A、B两站相向开出，在离A站60千米的地方相遇后，两车仍以原速度继续前进，各车分别到达对方出发点后立即返回，又在离B站30千米的地方相遇．问：A、B两站相距多少千米？
<gadget id="calculator">60 * 3</gadget>
<output>180</output>

<gadget id="calculator">180 - 30</gadget>
<output>150</output>

<result>150</result>