car drives from place A to place B, and travels the whole distance (2/5) in the first 4 hours. At this speed, how many hours will it take to complete the journey?
一辆汽车从甲地开往乙地，前4小时行了全程的(2/5)，照这样的速度，行完全程还要多少小时？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(2/5) / 4</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / (1/10)</gadget>
<output>10</output>

<gadget id="calculator">10 - 4</gadget>
<output>6</output>

<result>6</result>