If the height of a cuboid is reduced a little, the volume will be reduced by 20 cubic centimeters, and what remains is a cube with side lengths of 5 centimeters. How many centimeters will the height be reduced?
一个长方体，高减少一些后，体积就减少20立方厘米，剩下的是棱长5厘米的正方体，高减少了多少厘米．
<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">20 / 25</gadget>
<output>4/5 = around 0.8</output>

<result>4/5 = around 0.8</result>