On a map with a scale of 1:2000000, the distance between the two places is measured to be 20 centimeters, and it takes 5 hours for a car to travel the entire distance, how many kilometers does it travel on average per hour?
在比例尺是1：2000000的地图上，量得两地之间的距离是20厘米，一辆汽车行完全程用了5小时，平均每小时行多少千米？
<gadget id="calculator">1 / 2_000_000</gadget>
<output>1/2_000_000 = around 0</output>

<gadget id="calculator">20 / (1/2_000_000) / 100_000 / 5</gadget>
<output>80</output>

<result>80</result>