A cuboid reservoir covers an area of 20 square meters, the depth of the pond is 1.5 meters, and how many tons of water can be stored in the pond at most. (One cubic meter of water weighs 1 ton).
一个长方体蓄水池，占地20平方米，池深1.5米，池内最多蓄水多少吨．(每立方米水重1吨)．
<gadget id="calculator">20 * 1.5 * 1</gadget>
<output>30</output>

<result>30</result>