A car drives from place A to place B. It travels the whole distance (1/5) in the first hour, and travels 50 kilometers more in the second hour than in the first hour. At this time, it is still 280 kilometers away from place B. How far apart?
一辆汽车从甲地开往乙地，第一小时行全程的(1/5)，第二小时比第一小时多行50千米，这时离乙地还有280千米，甲乙两地相距多远？
<gadget id="calculator">280 + 50</gadget>
<output>330</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5) - (1/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">330 / (3/5)</gadget>
<output>550</output>

<result>550</result>