It is about 255km from Liuzhou to Nanning. There are two trains A and B going in opposite directions from a station in the middle at the same time, train A goes to Liuzhou, train B goes to Nanning, train A travels 23km per hour, and train B travels 27km per hour. In the end, the two vehicles A and B arrive at their respective destinations at the same time. How long does it take for A and B to travel each other?
从柳州到南宁大约有255km．有甲乙两列火车同时从中间的一个车站向相反方向开去，甲车去柳州，乙车去南宁，甲车每小时行23km，乙车每小时行27km．最后甲乙两车同时到达各自的目的地，甲乙两车各行了几小时？
<gadget id="calculator">23 + 27</gadget>
<output>50</output>

<gadget id="calculator">255 / 50</gadget>
<output>51/10 = around 5.1</output>

<result>51/10 = around 5.1</result>