On a map with a scale of 1:500000, the measured distance from A to B is 1.8 cm. How many hours does it take for Wang Ming to travel from point A to point B at a speed of 3.6 kilometers per hour?
在比例尺是1：500000的地图上，量得甲地到乙地的距离是1.8厘米．王明以每小时3.6千米的速度从甲地到乙地，需要几小时？
<gadget id="calculator">1 / 500_000</gadget>
<output>1/500_000 = around 0.000002</output>

<gadget id="calculator">1.8 / (1/500_000) / 100_000 / 3.6</gadget>
<output>2.5</output>

<result>2.5</result>