On the Beijing subway planning map with a scale of 1:100000, the measured length of Metro Line 1 is about 15cm. What is its actual length in km?
在比例尺为1：100000的北京地铁规划图上，量得地铁1号线长度大约是15cm，它的实际长度大约是多少km．
<gadget id="calculator">1 / 100_000</gadget>
<output>1/100_000 = around 0.00001</output>

<gadget id="calculator">15 / (1/100_000) / 100_000</gadget>
<output>15</output>

<result>15</result>