On a map with a scale of 1:2000000, the measured distance between A and B on the map is 1.5 cm. What is the actual distance between A and B in kilometers?
在比例尺是1：2000000的地图上，量的甲乙两地的图上距离是1.5厘米，甲乙两地的实际距离是多少千米．
<gadget id="calculator">1 / 2_000_000</gadget>
<output>1/2_000_000 = around 0</output>

<gadget id="calculator">1.5 / (1/2_000_000) / 100_000</gadget>
<output>30</output>

<result>30</result>