The railway from Beijing to Zhengzhou is 690 kilometers long. The train departs from Beijing at 10 am and arrives in Zhengzhou at 3 pm. How many kilometers does the train travel per hour?
北京到郑州的铁路长690千米，火车早上10时从北京出发，下午3时到达郑州，火车每小时行多少千米？
<gadget id="calculator">690 / 5</gadget>
<output>138</output>

<result>138</result>