On a map of 1:20000000, the distance between A and B is 3.5cm. What is the actual distance between A and B in KM?
在1：20000000的地图上量得甲乙两地的距离是3.5cm，甲乙两地的实际距离是多少KM．
<gadget id="calculator">1 / 20_000_000</gadget>
<output>1/20_000_000 = around 0</output>

<gadget id="calculator">3.5 / (1/20_000_000) / 100_000</gadget>
<output>700</output>

<result>700</result>