437.Coin on the Chessboard
★★★geometric probabilityCh. 2 — Axiomatic and Conditional Probability444+ Problems in Probability
A chessboard is made of 2-inch 2-inch squares. A coin of diameter 1 inch is tossed and lands uniformly at random on the board. What is the probability that the coin lies completely within a single square (touching no gridline)?
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Track the coin's center. How far must it stay from every gridline?
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