On a map with a scale of 1:5,000,000, the length of the road from Shanghai to Hangzhou is measured to be 3.4 cm. It takes 2 hours for a car to drive from Shanghai to Hangzhou, how many kilometers does it travel on average per hour?
在一幅比例尺是1：5000000的地图上，量得上海到杭州的公路长是3.4厘米．一辆汽车从上海开往杭州，用了2小时，平均每小时行多少千米？
<gadget id="calculator">1 / 5_000_000</gadget>
<output>1/5_000_000 = around 0</output>

<gadget id="calculator">3.4 / (1/5_000_000) / 100_000 / 2</gadget>
<output>85</output>

<result>85</result>