On a map with a scale of 1:6000000, the distance between A and B is 28 cm. A plane flies from A to B at 8:50 am and arrives at 10:50 am. How many kilometers does it fly per hour?
在比例尺为1：6000000的地图上，量得甲、乙两地的距离为28厘米，一架飞机上午8时50分从甲地飞往乙地，上午10点50分到达，这架飞机平均每小时飞行多少千米？
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">28 / (1/6_000_000) / 100_000 / 2</gadget>
<output>840</output>

<result>840</result>