A car starts from A to B, and travels the whole journey (2/5) in 3 hours. According to this calculation, how many hours will it take to complete the journey?
一辆汽车从甲地出发去乙地，3小时行了全程的(2/5)，照这样计算，行完全程还需要多少小时？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">3 / (2/5)</gadget>
<output>15/2 = around 7.5</output>

<gadget id="calculator">(15/2) - 3</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>