On a map with a scale of 1:300000000, the air route between the airports of A and B is measured to be 8 cm long. How long does it take for an airplane to fly from point A to point B at a speed of 800 kilometers per hour?
在一幅比例尺是1：300000000的地图上，量得A、B两地机场航线长8厘米，一架飞机以每小时800千米的速度从A地飞往B地，需几小时？
<gadget id="calculator">1 / 300_000_000</gadget>
<output>1/300_000_000 = around 0</output>

<gadget id="calculator">8 / (1/300_000_000) / 100_000 / 800</gadget>
<output>30</output>

<result>30</result>