Here are a few puzzles paraphrased from What is the Name of This Book? by Raymond Smullyan. They're set in the world of Alice in Wonderland, in the Forest of Forgetfulness (now, I don't know if this is from the original book or if it's a Smullyan original). Alice doesn't remember very much, but she does know that the Lion lies on Mondays, Tuesdays, and Wednesdays, telling the truth on the rest of the days of the week. The Unicorn lies on Thursdays, Fridays, and Saturdays, and tells the truth the rest of the week.
1. What day of the week is it if the Lion and the Unicorn make these statements on the same day? Lion: Yesterday was one of my lying days. Unicorn: Yesterday was one of my lying days, too.
2. What day of the week is it if the Lion says these two things? a) I lied yesterday. b) I will lie again two days after tomorrow.
3. What day of the week is it if the Lion says these two other things? a) I lied yesterday. b) I will lie again tomorrow.
Answers
First: The only days the Lion could make that statement are Mondays and Thursdays; the Unicorn could only make that statement on Thursdays and Sundays. It must, therefore, be Thursday.
Second: a) means it must be Monday or Thursday; b) means it can't be Thursday. It is Monday!
Third: Trick question! There's no day of the week when he can say both.
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timeasmymeasure
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Date: 2024-10-29 10:38 pm (UTC)Here are a few puzzles paraphrased from What is the Name of This Book? by Raymond Smullyan. They're set in the world of Alice in Wonderland, in the Forest of Forgetfulness (now, I don't know if this is from the original book or if it's a Smullyan original). Alice doesn't remember very much, but she does know that the Lion lies on Mondays, Tuesdays, and Wednesdays, telling the truth on the rest of the days of the week. The Unicorn lies on Thursdays, Fridays, and Saturdays, and tells the truth the rest of the week.
1. What day of the week is it if the Lion and the Unicorn make these statements on the same day?
Lion: Yesterday was one of my lying days.
Unicorn: Yesterday was one of my lying days, too.
2. What day of the week is it if the Lion says these two things?
a) I lied yesterday.
b) I will lie again two days after tomorrow.
3. What day of the week is it if the Lion says these two other things?
a) I lied yesterday.
b) I will lie again tomorrow.
Answers
First
: The only days the Lion could make that statement are Mondays and Thursdays; the Unicorn could only make that statement on Thursdays and Sundays. It must, therefore, be Thursday.Second
: a) means it must be Monday or Thursday; b) means it can't be Thursday. It is Monday!Third
: Trick question! There's no day of the week when he can say both.