A city is about 60 kilometers long from north to south. On a map with a scale of 1/250000, the east-to-west length of the city is 18 cm. What is the actual distance in kilometers?
某城市南北长约60千米，在比例尺是1/250000的地图上量得城市东西长18厘米，东西的实际距离大约是多少千米．
<gadget id="calculator">1 / 250_000</gadget>
<output>1/250_000 = around 0.000004</output>

<gadget id="calculator">18 / (1/250_000) / 100_000</gadget>
<output>45</output>

<result>45</result>