On a map with a scale of 1:60000000, the distance between A and B is 2.5 centimeters. A plane flies from A to B at 8:30 am and arrives at 11 am. How many kilometers per hour does the plane fly on average?
在比例尺是1：60000000的地图上，量得甲乙两地的航线距离是2.5厘米，上午8时30分有一架飞机从甲地飞往乙地，上午11时到达．这架飞机平均每小时飞行多少千米．
<gadget id="calculator">1 / 60_000_000</gadget>
<output>1/60_000_000 = around 0</output>

<gadget id="calculator">2.5 / (1/60_000_000) / 100_000 / 2.5</gadget>
<output>600</output>

<result>600</result>