Tag Archives: Parity Puzzles

Solution to Puzzle #196: Bugs on a Board

Posted on October 15, 2017 by Alok Goyal

Apologies for not posting anything in the last few weeks, was traveling on work or vacation through this period. This was not a very difficult puzzle, but I got correct answers only from the two people who solve every puzzle … Continue reading →

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Solution to Puzzle #195: 1989!

Posted on September 24, 2017 by Alok Goyal

I received many correct answers. These included  Suman Saraf, Vishal Poddar and Anand Sanghi. Thank you and well done! This puzzle can be solved using the concept of “invariants” and parity. Note that for any numbers a and b (a … Continue reading →

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Puzzle #195: 1989!

Posted on September 10, 2017 by Alok Goyal

This is a beautiful puzzle from Mathematical Circles (Russian Experience) by Dmitri Fomin, Sergey Genkin and Ilia Itenberg. There numbers 1, 2, 3, ….. , 1989 are written on a blackboard. It is permitted to erase any two of them … Continue reading →

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Puzzle #193: Smallville Telephones

Posted on August 27, 2017 by Alok Goyal

This is a relatively simple puzzle from Mathematical Circles by Dmitri Fomin, Sergey Genkin and Ilia Itenberg. Please do share this with your children, they should enjoy this. In Smallville, there are 15 telephones. Can they be connected by wires … Continue reading →

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Solution to Puzzle #191: 1×4 Rectangular Stone Plates

Posted on August 27, 2017 by Alok Goyal

This was one of my favorite puzzles, though slightly difficult. Unfortunately I got only one correct answer this time, from Suman Saraf. Well done Suman! The answer is “no”. Look at the unusual coloring of the 10×10 board above. Please … Continue reading →

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Solution to Puzzle #180: White and Black Beans

Posted on May 28, 2017 by Alok Goyal

This was one of the simpler puzzles and I got correct answers from many. This included Mahi Saraf, Anahat (Prakhar’s son), Vishal Poddar, Pratik Poddar and Praneeth. Well done all. The answer is “white”. I am borrowing the answer from … Continue reading →

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Puzzle #91: Pebble Piles

Posted on February 8, 2015 by Alok Goyal

Another very nice puzzle I read on gurmeet.net/puzzles/, which as I have mentioned before, has a set of very nice mathematical puzzles. You are given three piles with 5, 49 and 51 pebbles respectively. Two operations are allowed: (a) merge two … Continue reading →

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