On a map with a scale of 1:50000000, the distance between A and B is 2.5 cm. What is the actual distance in miles between A and B?
在比例尺是1：50000000的地图上，量得A、B两地的距离为2.5厘米．A、B两地的实际距离为多少千米．
<gadget id="calculator">1 / 50_000_000</gadget>
<output>1/50_000_000 = around 0</output>

<gadget id="calculator">2.5 / (1/50_000_000) / 100_000</gadget>
<output>1_250</output>

<result>1_250</result>