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Problem 23 (2023 AMC 8)

AMC 8Hard

From module Introduction to Probability

Problem

Each square in a 3×33 \times 3 grid is randomly filled with one of the 44 gray-and-white tiles shown below on the right. What is the probability that the tiling will contain a large gray diamond in one of the smaller 2×22 \times 2 grids? Below is an example of one such tiling. [See figure in original PDF]

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