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2005 AMC 10B Question 8

AMC10 · 2005 AMC 10B

Question 8

An $8$-foot by $10$-foot floor is tiled with square tiles of size $1$ foot by $1$ foot. Each tile has a pattern consisting of four white quarter circles of radius $\dfrac12$ foot centered at each corner of the tile. The remaining portion of the tile is shaded. How many square feet of the floor are shaded?

Question illustration
  1. $80 - 20\pi$
  2. $60 - 10\pi$
  3. $80 - 10\pi$
  4. $60 + 10\pi$
  5. $80 + 10\pi$