On a map with a scale of 1:3000000, what is the actual distance in kilometers represented by a line segment 2.5 cm long on the map.
在比例尺是1：3000000的地图上，图上2.5厘米长的线段表示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>