A small cylindrical oil barrel is filled with oil, and the oil in the barrel is poured out (2/5), and there are 24 liters left. The bottom area of the oil barrel is 10 square decimeters, what is the height of the oil barrel? (The thickness of the iron sheet of the oil drum is ignored)
一个圆柱形小油桶里装满了油，把桶里的油倒出(2/5)，还剩24升．油桶的底面积是10平方分米，这个油桶的高是多少分米？(油桶铁皮的厚度忽略不计)
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">24 / (3/5) / 10</gadget>
<output>4</output>

<result>4</result>