On a map with a scale of 1:6000000, the distance between A and B is 12cm. How many hours does it take for a train to travel from point A to point B at a speed of 180 kilometers per hour?
在一幅比例尺是1：6000000地图上，量得A、B两地之间的距离是12cm．一列火车以每小时180千米的速度从A地开往B地，全程需要多少小时？
<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">12 / (1/6_000_000) / 100_000 / 180</gadget>
<output>4</output>

<result>4</result>