Is it possible to create a 3 x 3 matrix, using only the numbers -1, 0, and 1 such that all six row and column sums are distinct?
***Adapted from OSSMB 84-7
(In reply to
Slightly different solution by Jer)
This proof is not complete, Jer. It fails to rule out sums of -2,-1,0,1,2,3, where 3 and -2 are both row sums.