On a map with a scale of 1:30000, the distance between A and B is 9.9 cm. What is the actual distance between A and B in kilometers?
在一副比例尺是1：30000的地图上，量得A、B两地间距离为9.9cm，AB两地实际距离是多少千米．
<gadget id="calculator">1 / 30_000</gadget>
<output>1/30_000 = around 0.000033</output>

<gadget id="calculator">9.9 / (1/30_000) / 100_000</gadget>
<output>2.97</output>

<result>2.97</result>