Ponder This: October’s Challenge!

Are you a professional problem solver? If so, we invite you to submit your “Ponder This” solution for this month’s challenge.  Ponder This is IBM Research’s monthly brain-twister where you can match wits with some of the best minds at IBM.

Ponder This Challenge:

Color the squares of an 8×8 check-board in two colors (black and white) and calculate the percentage of black squares in every one of the 8 rows, 8 columns and 30 diagonals.

Our challenge this month is to find such coloring which gives the same percentage for every row; different one for every column and as many different numbers in the diagonals as possible.

Supply your answer as 8 lines of 8 B/W characters.

For example, the following is a solution for a 2×2 case of the problem:

The column percentage is 0%, 100%; all rows are 50% and the diagonals has 0%,50% and 100% (each appears twice).


IBM Research will post the names of those who submit a correct, original solution to their website! If you don’t want your name posted then please include such a statement in your submission. Send your submission to the webmaster.

If you have any problems you think we might enjoy, please send them in. All replies should be sent to: webmster@us.ibm.com

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