The distance from Beijing to Nanjing measured on a map with a scale of 1:4500000 is 20 centimeters. How long should it be drawn on a map with a scale of 1:6000000?
在比例尺为1：4500000的地图上量得北京到南京的距离是20厘米，如果改画在比例尺为1：6000000的地图上应画多长？
<gadget id="calculator">1 / 4_500_000</gadget>
<output>1/4_500_000 = around 0</output>

<gadget id="calculator">20 / (1/4_500_000)</gadget>
<output>90_000_000</output>

<gadget id="calculator">1 / 6_000_000</gadget>
<output>1/6_000_000 = around 0</output>

<gadget id="calculator">90_000_000 * (1/6_000_000)</gadget>
<output>15</output>

<result>15</result>