On a map with a scale of 1:4,000,000, the distance between Tianjin and Beijing is measured to be 3 centimeters. A train travels from Tianjin to Beijing at a speed of 100 kilometers per hour. How long does it take to get there?
在比列尺1：4000000的地图上，量得天津到北京的距离是3厘米．一辆火车以每小时100千米的速度从天津开北京，几小时能到达？
<gadget id="calculator">1 / 4_000_000</gadget>
<output>1/4_000_000 = around 0</output>

<gadget id="calculator">3 / (1/4_000_000) / 100_000 / 100</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>