This is the first puzzle, slightly Americanized, in the "Miscellaneous—Easy" section of Brain Puzzler's Delight, by E. R. Emmet. I doubt I'll solve many in the "Miscellaneous—Hard" section.
George, John, Arthur and David are married, but not necessarily respectively, to Christine, Eve, Prudence and Rose. They remember that at a party years ago various predictions had been made. George had said that John would not marry Christine. John had said that Arthur would marry Prudence. Arthur had predicted that whoever David married it would not be Eve. David, who at that time was more interested in baseball than in matrimony, had predicted that the Yankees would win the World Series next year. The only one to predict correctly was the man who later married Prudence.
Who married whom? Did the Yankees win the World Series the next year?
Hint: Start with John's prediction and the rule about the man who married Prudence.
Answer: According to the puzzle, only one man married Prudence, and he was the only man to predict correctly.
Had John predicted correctly, both he and Arthur would've married Prudence, so John didn't predict correctly, and so he must not have married Prudence.
Because John didn't predict correctly, we know that Arthur didn't marry Prudence, and so he must not have predicted correctly.
Because Arthur didn't predict correctly, David must've married Eve.
Because David married Eve, he can't have married Prudence, and so he must not have predicted correctly.
Thus George must be the man who married Prudence and predicted correctly.
George predicted (correctly) that John wouldn't marry Christine, so with David married to Eve and George married to Prudence, John must've married Rose.
Thus Arthur must've married Christine.
And because David didn't predict correctly, the Yankees must not have won the World Series.
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