The Hooded Man Paradox: Knowing And Not Knowing Your Brother At The Same Time

Eubulides of Miletus (c. 400 BC), a philosopher of the Megarian school and a student of Euclid of Megara (not to be confused with Euclid of Alexandria who compiled the Elements of Euclid), posed the following paradox: You say you know your brother. Yet when your brother is hooded you are unable to identify him. […]

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Introducing Raymond Smullyan

One day, when a speaker was introducing logician and puzzlist Raymond Smullyan, he remarked that “Professor Smullyan is unique.” Smullyan, who was feeling playful that day, said, “I’m sorry to interrupt you Sir but I happen to be the only one in the entire universe who is not unique.” On another event, Smullyan was introduced […]

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Constructing Rectangles With Jigsaw Puzzle

What is the smallest rectangle which can be made by using jigsaw pieces of these two shapes only? What is the next smallest such rectangle? What rectangles are possible using these shapes only? (Note: You can use no matter how many of these two jigsaw pieces as you see fit.)

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Lewis Carroll’s Weird Sylogisms

A syllogism is a form of logical argument in which a conclusion is drawn from two or more premises that are assumed to be true using deductive reasoning. For instance, 1. All men are mortal. 2. Socrates is a man. Therefore Socrates is mortal.

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A Logical Meal

Four logicians were having dinner and discussing logical puzzles. After the main course, the waiter brought a large plate that contains 11 slices of cakes. Their debate was intense and in the process, they ended up eating all the cakes. Everyone had at least eaten one cake, and each of them is aware of that […]

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The Truth-Teller And The Liar Puzzle

Veritas and Truth are sisters. One of them (we don’t have any idea who) always tells the truth while the other always lies. Alex questioned one of them: “Is Truth the one that lies?” “Yes,” she replied. Did Alex speak to Veritas or Truth?

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