On a map with a scale of 1:2000000, the distance between A and B is 25 cm. Two trains depart from the two places at the same time. After 4 hours, the two trains have not met, and the distance is still 20 kilometers. Knowing that a train travels 65 kilometers per hour, what is the speed of the other train?
在比例尺是1：2000000的地图上，量得甲、乙两地的距离为25厘米，两列火车同时从两地相对开出，4小时后两车还没相遇，还相距20千米，已知一列火车每小时行65千米，求另一列火车的速度是多少？
<gadget id="calculator">80 - 65</gadget>
<output>15</output>

<result>15</result>