Black squares are pentagons and white squares are hexagons. The five sides of each black leather are sewn together with one side of five white leather respectively. Three sides of each white leather are sewn together with three black leather.
If white skin has x blocks, it has 6x sides. Among the 6x edges, one part is connected with white skin, and the other part is connected with black skin. Obviously, there are 3x edges connected with black skin.
Solution:
Let white leather * * * have x pieces, then it * * * has 6x sides, and the number of sides stitched with black leather is 3x. According to statistics, there are 12 black skins, and each black skin has 5 sides, so the black skin * * * has 5× 12=60 sides. According to the meaning of the question, it means: 3x=60.
Solve this equation and get x=20.
So, there are 20 pieces of white skin.
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According to the landlord, the black leather is 22 pieces and the white leather is 22×5/3, which are inseparable. No solution, right? Aha.