The local train and the express train leave oppositely from stations A and B respectively, meet each other after 30 minutes, and continue to move forward at the original speed after meeting, and after another 7 (1/2) minutes, the local train arrives at the midpoint of the two stations. When the express train arrives at station B, the slow train is still 120 kilometers away from station A. How many kilometers are there between the two stations?
慢车和快车分别从甲乙两站相对开出，经过30分钟相遇，相遇后仍以原速前进，又经过7(1/2)分钟，慢车到达两站中点．当快车到达乙站时，慢车离甲站还有120千米，甲乙两站相距多少千米？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">120 * 5</gadget>
<output>600</output>

<result>600</result>