If the height of a cuboid is increased by 2cm, it will become a cube. At this time, the surface area is increased by 64cm. What is the volume of the original cuboid 2. Dig out a small piece from a cuboid wood block with a volume of 30cm. What is its surface area; 3. How much is the surface area reduced by kneading a 8cm long, 4cm wide and 2cm high dough into a cube?

1. Let the side length of the bottom surface be D, that is, 4D * 2 = 64, d = 8, original H = 6, v = 8 * 8 * 6 = 384
2、30
3. Original surface area = 2 * (8 * 4 + 8 * 2 + 4 * 2) = 112
If the volume is 8 * 4 * 2 = 64, the side length of the cube is 4 and the surface area is 6 * 4 * 4 = 96
Reduced 112-96 = 16

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