It took a train 4.5 hours to travel 324 kilometers from Nanjing to Shanghai, how many kilometers per hour on average?
一列火车从南京到上海行驶324千米用了4.5小时，平均每小时行多少千米？
<gadget id="calculator">324 / 4.5</gadget>
<output>72</output>

<result>72</result>