The scale of a picture is 1:5000000, if the distance on the picture is 3 cm, how many kilometers is the actual distance?
一幅图的比例尺是1：5000000，如果图上距离是3厘米，那么实际距离是多少千米．
<gadget id="calculator">1 / 5_000_000</gadget>
<output>1/5_000_000 = around 0</output>

<gadget id="calculator">3 / (1/5_000_000) / 100_000</gadget>
<output>150</output>

<result>150</result>