A car travels from city A to city B on the first day of the whole journey (1/10). If it travels another 160 kilometers, it can travel half of the journey. What is the length of the highway from city A to city B?
一辆汽车从A城到B城，第一天行驶的路程是全程的(1/10)，如果再行驶160千米，就可以行驶到全程的一半．问从A城到B城的公路长是多少千米？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/2) - (1/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">160 / (2/5)</gadget>
<output>400</output>

<result>400</result>