Let us place at random the digits from 1 to 9 into the cells of 3x3 square.
What is the probability of getting a configuration such that the 8 sums (3 rows, 3 columns and 2 main diagonals) will be represented by 8 distinct numbers?
Construct at least one such square.

Extra challenge:
Same two tasks for 4x4 square , numbers 1 to 16 and 10 distinct sums.

(In reply to re(2): computer solution by Charlie)

Please check again the wrong sums at the diagonals - apparently the 9th number is stuck at 22.

It would be of interest to hear from you about the nature of the bug  and the process of verification.

Posted by Ady TZIDON on 2011-07-13 03:20:19