Tag Archives: logic puzzles

Solution to Puzzle #196: Bugs on a Board

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

Posted in Solution | Tagged , , , | Leave a comment

Solution to Puzzle #195: 1989!

I received many correct answers. These included ┬áSuman 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

Posted in Solution | Tagged , , | Leave a comment

Puzzle #196: Bugs on a Board

Yet another very fine puzzle from A Moscow Math Circle: Week by Week Problems by Sergey Dorichenko. Each square of a 9 x 9 board has a bug sitting on it. On a signal, each bug crawls onto one of … Continue reading

Posted in Puzzles | Tagged , , | 1 Comment

Solution to Puzzle #194: Adjacent Cells on a Chessboard

I got only two correct answers for this puzzle – from Suman Saraf and Pratik Poddar – thank you both and well done! I am taking the liberty of copying the answer from Pratik – I find it to be … Continue reading

Posted in Solution | Tagged , | Leave a comment

Puzzle #195: 1989!

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

Posted in Puzzles | Tagged , , , | 4 Comments

Puzzle #194: Adjacent Cells On a Chessboard

This is another beauty of a puzzle from A Moscow Math Circle: Week by Week Problems by Sergey Dorichenko. The numbers from 1 to 64 have been placed in each square on a chessboard such that each number appears exactly … Continue reading

Posted in Puzzles | Tagged , , | 1 Comment

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

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

Posted in Solution | Tagged , , , | Leave a comment