A car drives from city A to city B, traveling 54 kilometers per hour, and arrives in 5 hours. When returning, because it is an uphill road, the hour is 20% slower than before. How many hours did it take to return? (Solve using ratio method)
一辆汽车从甲城开往乙城，每小时行驶54千米，5小时到达．返回时因是上坡路，每小时比原来慢了20%．返回时用了多少小时？(用比例方法解答)
<gadget id="calculator">54 * 5</gadget>
<output>270</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">54 * (1/5)</gadget>
<output>54/5 = around 10.8</output>

<gadget id="calculator">54 - (54/5)</gadget>
<output>216/5 = around 43.2</output>

<gadget id="calculator">270 / (216/5)</gadget>
<output>25/4 = around 6.25</output>

<result>25/4 = around 6.25</result>