EACH OF THE NUMBERS 1, 2, 3, 4, 5, 6, 7, 8 AND 9 IS TO BE PLACED IN...

1.

Each of the numbers 1, 2, 3, 4, 5, 6, 7, 8 and 9 is to be placed in a di fferent

square of a 3×3 table. We color the largest number in each row, red while the

smallest number in each row, green. Let M be the smallest among the three red

numbers, and m be the largest among the three green numbers. Determine all

possible values of M − m.