On a map with a scale of (1/50000), the distance from Beijing to Tianjin is 28 centimeters. If the train travels 80 kilometers per hour, how long will it take to travel from Tianjin to Beijing by train?
在比例尺是(1/50000)的地图上，量得北京到天津的距离是28厘米．若火车每小时行80千米，坐火车从天津到北京要几小时？
<gadget id="calculator">1 / 50_000</gadget>
<output>1/50_000 = around 0.00002</output>

<gadget id="calculator">28 / (1/50_000) / 100_000 / 80</gadget>
<output>7/40 = around 0.175</output>

<result>7/40 = around 0.175</result>