On a map with a scale of 1:400000, the distance between A and B is 15 cm. What is the actual distance in kilometers between A and B?
在一幅比例尺是1﹕400000的地图上，量得甲乙两地的距离是15厘米．甲乙两地的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">15 / (1/400_000) / 100_000</gadget>
<output>60</output>

<result>60</result>