cube glass tank, the side length measured from the inside is 20cm. Fill the tank with water and pour it into an empty cuboid goldfish bowl. It is known that the length, width, and height of a goldfish bowl measured from the inside are 40cm, 20cm, and 30cm, respectively. How deep is the water in the goldfish bowl?
一个正方体玻璃水槽，从里面量得棱长是20cm．用这个水槽装满水，再倒入一个空的长方体金鱼缸中．已知从里面量得金鱼缸的长、宽、高分别是40cm、20cm、30cm．金鱼缸中水的深度是多少厘米？
<gadget id="calculator">40 * 20</gadget>
<output>800</output>

<gadget id="calculator">20 / 800</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">20 * 20 * (1/40)</gadget>
<output>10</output>

<result>10</result>