The length of the railway between A and B is 306 kilometers. A train departs from A at 9:00 am and arrives at B at 1:30 pm. How many kilometers per hour does the train travel on average?
甲、乙两站之间的铁路长306千米，一列火车上午9：00从甲站出发，下午1：30到达乙站，这列火车平均每小时行多少千米？
<gadget id="calculator">306 / 4.5</gadget>
<output>68</output>

<result>68</result>