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VTMO 2022 — Grade 9 — vtmo Question 17

VTMO · VTMO 2022 — Grade 9 — vtmo

Question 17

$A = 5 \times 5$ board has a light in every cell. Pressing a cell toggles it and its edge-neighbors. Initially only the central light is off and all others are on as pictured. Can all lights be switched off?

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