perplexus.info :: Paradoxes

Home > Paradoxes

These problems may or may not have an actual solution. Some of them are flat out contradictions, some lead you into infinite loops of logic.

Latest: SupraRef Indexing Rating: 5.00

A very large book SupraRef refers to its index every book that does NOT refer to itself in the index.

Does SupraRef refer to itself in the index? Provide valid reasoning for your answer.

Submitted on 2023-03-10 by K Sengupta

Page 2 of 3

<< prev next >>

Provably unprovable? | Rating: 3.42
Posted on 2004-08-22 by Federico Kereki (Solution Posted, 36 Comments)

The grass is always greener... | Rating: 3.94
Posted on 2004-05-06 by Gamer (No Solution Yet, 46 Comments)

Poisonous Dilemma | Rating: 3.85
Posted on 2004-04-19 by Victor Zapana (No Solution Yet, 84 Comments)

Shortest Long Number | Rating: 3.08
Posted on 2004-04-15 by Sam (Solution Posted, 49 Comments)

On the house? | Rating: 3.76
Posted on 2003-10-31 by SilverKnight (Solution Posted, 25 Comments)

Marbles Bonanza | Rating: 3.62
Posted on 2003-09-08 by levik (Solution Posted, 87 Comments)

No,no,no | Rating: 3.65
Posted on 2003-06-04 by Tim Axoy (Solution Posted, 53 Comments)

All dogs are the same color! | Rating: 3.50
Posted on 2003-05-30 by Fernando (Solution Posted, 23 Comments)

True Or False - Part 2 | Rating: 2.50
Posted on 2003-05-07 by Ravi Raja (Solution Posted, 45 Comments)

Can Or Cannot | Rating: 3.58
Posted on 2003-04-30 by Ravi Raja (Solution Posted, 110 Comments)

True Or False - Part 1 | Rating: 2.60
Posted on 2003-04-24 by Ravi Raja (Solution Posted, 45 Comments)

The two blacksmiths | Rating: 3.07
Posted on 2003-03-17 by Gareth (Solution Posted, 65 Comments)

Aliens | Rating: 3.33
Posted on 2003-03-15 by ross jaenke (Solution Posted, 40 Comments)

Achilles and the Tortoise | Rating: 3.08
Posted on 2002-11-22 by Raveen (Solution Posted, 31 Comments)

Liar or not? | Rating: 2.71
Posted on 2002-11-12 by Raveen (Solution Posted, 38 Comments)

Please log in:

Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (0)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info