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Narayan singh Best Answer
There are 2^3 = 8 possible outcomes after tossing a fair coin fairly 3 times. The 8 possible outcomes are: TTT, TTT, THT, TTH, HHT, HTH, THH, HHH. Exactly 2 of 8 possible outcomes result in 3 of the same faces showing up. They are TTT and HHH. Each has a probability of 1/8 of happening and since either showing up satisfactorily addresses the criterion for success, so the probability as requested = 2*(1/8) = 1/4 = .25 = 25%.