On a map with a scale of 1:400000, the distance between A and B is measured to be 3 cm, so what is the actual distance in kilometers between A and B?
在一幅比例尺是1：400000的地图上，量得甲乙两地距离为3厘米，那么甲乙两地实际距离是多少千米．
<gadget id="calculator">1 / 400_000</gadget>
<output>1/400_000 = around 0.000002</output>

<gadget id="calculator">3 / (1/400_000) / 100_000</gadget>
<output>12</output>

<result>12</result>