On a map with a scale of 1:250000, the distance between AB and AB is 50 kilometers. What is the distance between AB and AB on the map?
在比例尺是1：250000的图上，AB两地的距离是50千米，AB两地在地图上的距离是多少厘米．
<gadget id="calculator">1 / 250_000</gadget>
<output>1/250_000 = around 0.000004</output>

<gadget id="calculator">50 * 100_000 * (1/250_000)</gadget>
<output>20</output>

<result>20</result>