There is a cuboid pool filled with water. The bottom area of the pool is 20 square meters and the depth is 3 meters. Now how many cubic meters of water is left in the pool after (2/5) of the water in the pool is used up?
有一个长方体的水池装满水，水池的底面积为20平方米，深3米，现用去这个水池里面水的(2/5)后，求水池中还剩多少立方米的水？
<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">20 * 3 * (3/5)</gadget>
<output>36</output>

<result>36</result>