On a map with a scale of 1:3000000, the distance between A and B is 2.5 cm. What is the actual distance between A and B in kilometers?
在比例尺为1：3000000的地图上，量得A、B两地的距离是2.5厘米，A、B两地的实际距离是多少千米．
<gadget id="calculator">1 / 3_000_000</gadget>
<output>1/3_000_000 = around 0</output>

<gadget id="calculator">2.5 / (1/3_000_000) / 100_000</gadget>
<output>75</output>

<result>75</result>