Two cars, A and B, are driving from city A to city B at the same time. It was originally planned that car A will arrive 1 hour earlier than car B. After driving for 8 hours, due to heavy rain, car A decelerates (2/5) and car B decelerates (1/5) 4), the last two cars arrive at city B at the same time. How many hours did it actually take for A and B to travel from city A to city B?
甲、乙两车同时从A城开往B城，原计划甲车比乙车早1小时到达，行驶8小时后，由于下大雨，甲车减速(2/5)，乙车减速(1/4)，最后两车同时到达B城．甲、乙两车从A城到B城实际用了多少小时？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

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

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(5/3) - (4/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / (3/4) / (1/3)</gadget>
<output>4</output>

<gadget id="calculator">4 + 8</gadget>
<output>12</output>

<result>12</result>