Cars A and B both drive from point A to point B. The express delivery of car B is 20% slower than that of car A. It takes 6 hours for car A to complete the journey. How many hours does it take for car B to complete the journey?
甲、乙两车都从A地开往B地，乙车的速递比甲车慢20%，甲车行完全程要6小时，乙车行完全程要多少小时？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">6 / (4/5)</gadget>
<output>15/2 = around 7.5</output>

<result>15/2 = around 7.5</result>