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MathNet 2008-part-05 — 164 problems (EN–VI) Question 128

Math Olympiad Vault · MathNet 2008-part-05 — 164 problems (EN–VI)

Question 128

Joe B. is frustrated with chess. He breaks the board, leaving a $4 \times 4$ board, and throws 3 black knights and 3 white kings at the board. Miraculously, they all land in distinct squares! What is the expected number of checks in the resulting position? (Note that a knight can administer multiple checks and a king can be checked by multiple knights.)