On a map with a scale of 1:300000, the distance between A and B is 15 cm. Please calculate the actual distance between A and B in kilometers?
在一幅比例尺是1：300000的地图上，量得A、B两地的距离是15厘米，请你计算出A、B两地之间的实际距离是多少千米？
<gadget id="calculator">1 / 300_000</gadget>
<output>1/300_000 = around 0.000003</output>

<gadget id="calculator">15 / (1/300_000) / 100_000</gadget>
<output>45</output>

<result>45</result>