1 centimeter on a map represents the actual distance of 50 kilometers. The distance from Xi'an to Shanghai is measured on this map as 30 centimeters. What is the actual distance in kilometers from Xi'an to Shanghai?
一幅地图上1厘米代表实际距离50千米．在这幅地图上量得西安到上海的距离为30厘米，西安到上海的实际距离是多少千米．
<gadget id="calculator">50 * 100_000</gadget>
<output>5_000_000</output>

<gadget id="calculator">1 / 5_000_000</gadget>
<output>1/5_000_000 = around 0</output>

<gadget id="calculator">30 / (1/5_000_000) / 100_000</gadget>
<output>1_500</output>

<result>1_500</result>