Problems & Puzzles: Puzzles

Puzzle 965. Partitioning an 8x8 square Fausto Morales sent the following nice puzzle: Find the unique partition of the 8x8 square below into the 10 smallest primes containing digits 1 and 9 only, so that each prime appears once left-to-right and once top-to-bottom.   1 9 9 9 1 9 9 1 9 1 1 1 1 9 1 9 1 1 9 1 1 1 1 9 9 9 1 1 1 1 1 9 9 1 9 9 1 9 1 1 9 9 1 9 1 9 9 9 1 9 9 1 9 9 1 1 1 9 1 9 1 9 9 9 The 10 smallest primes mentioned above are; 11, 19, 191, 199, 911, 919, 991, 1999, 9199, 11119 Q1. Send your partition-solution. A solved example: If the 8x8 matriz is: 1 9 1 9 9 9 1 1 9 1 1 9 1 9 9 9 9 1 9 1 9 1 9 1 9 1 1 1 9 9 1 9 1 1 1 1 1 1 9 1 9 9 1 1 9 9 9 9 9 1 1 1 1 9 1 9 1 9 9 9 1 9 1 9 The solution is this one: 1 9 1 9 9 9 1 1 9 1 1 9 1 9 9 9 9 1 9 1 9 1 9 1 9 1 1 1 9 9 1 9 1 1 1 1 1 1 9 1 9 9 1 1 9 9 9 9 9 1 1 1 1 9 1 9 1 9 9 9 1 9 1 9

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Contributions came from Michael Hürter, Oscar Volpatti

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Michael wrote on Aug 10, 2019:

1	9	9	9	1	9	9	1
9	1	1	1	1	9	1	9
1	1	9	1	1	1	1	9
9	9	1	1	1	1	1	9
9	1	9	9	1	9	1	1
9	9	1	9	1	9	9	9
1	9	9	1	9	9	1	1
1	9	1	9	1	9	9	9

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Oscar wrote on Aug 12, 2019:

This is my four-coloured solution, with five partitions and sixteen digits per colour:

 

1 9 9 9 1 9 9 1

9 1 1 1 1 9 1 9

1 1 9 1 1 1 1 9

9 9 1 1 1 1 1 9

9 1 9 9 1 9 1 1

9 9 1 9 1 9 9 9

1 9 9 1 9 9 1 1

1 9 1 9 1 9 9 9

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