On a map, the distance between cities A and B is 7 cm. The scale of this map is 1:500,000. What is the actual distance between cities A and B in kilometers?
在一幅地图上，量得A、B两城市之间的距离是7厘米，这幅地图的比例尺是1：500000，那么A、B两城市之间的实际距离是多少千米．
<gadget id="calculator">1 / 500_000</gadget>
<output>1/500_000 = around 0.000002</output>

<gadget id="calculator">7 / (1/500_000) / 100_000</gadget>
<output>35</output>

<result>35</result>