Question 16
The three row sums and the three column sums of the array $$
\begin{bmatrix} 4&9&2\\ 8&1&6\\ 3&5&7 \end{bmatrix}
$$ are the same. What is the least number of entries that must be altered to make all six sums different from one another?
\begin{bmatrix} 4&9&2\\ 8&1&6\\ 3&5&7 \end{bmatrix}
$$ are the same. What is the least number of entries that must be altered to make all six sums different from one another?