A map with a scale of 1:9,000,000 measures 8 centimeters from Beijing to Shanghai. A train travels from Shanghai to Beijing and travels 240 kilometers in 2 hours. At this speed, how many hours does it take to travel from Shanghai to Beijing?
一幅比例尺为1：9000000的地图上量得北京到上海的举例是8厘米，一列火车从上海开往北京，2小时行驶240千米，照这样的速度，从上海到北京需要几小时？
<gadget id="calculator">1 / 9_000_000</gadget>
<output>1/9_000_000 = around 0</output>

<gadget id="calculator">240 / 2</gadget>
<output>120</output>

<gadget id="calculator">8 / (1/9_000_000) / 100_000 / 120</gadget>
<output>6</output>

<result>6</result>