Uncle Wang drove from Beijing to Shanghai. From the beginning, the speed of the car was increased (1/9) than the original plan, and he arrived one and a half hours earlier; Increase (1/6), so I arrived in Beijing 1 hour and 40 minutes earlier. How many kilometers is the distance between Beijing and Shanghai?
王叔叔开车从北京到上海，从开始出发，车速就比原计划的速度提高了(1/9)，结果提前一个半小时到达；返回时，按原计划的速度行驶280千米后，将车速提高(1/6)，于是提前1小时40分到达北京．北京、上海两市间的路程是多少千米．
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1.5 / (1/10)</gadget>
<output>15</output>

<gadget id="calculator">5 / 3</gadget>
<output>5/3 = around 1.666667</output>

<gadget id="calculator">(5/3) * 7</gadget>
<output>35/3 = around 11.666667</output>

<gadget id="calculator">15 - (35/3)</gadget>
<output>10/3 = around 3.333333</output>

<gadget id="calculator">280 / (10/3)</gadget>
<output>84</output>

<gadget id="calculator">15 * 84</gadget>
<output>1_260</output>

<result>1_260</result>