Two trains depart from cities A and B at the same time. One train travels 120 kilometers per hour, and the other train travels 95 kilometers per hour. They meet after 3 hours. How many kilometers are the distance between cities A and B?
两列火车同时从甲、乙两城相对开出，一列火车每小时行120千米，另一列火车每小时行95千米，经过3小时后相遇，甲、乙两城相距多少千米？
<gadget id="calculator">120 + 95</gadget>
<output>215</output>

<gadget id="calculator">215 * 3</gadget>
<output>645</output>

<result>645</result>