Arrange nine digits in a 3x3 array such that each different digit that appears appears as many times as its cardinality, so for example, if the digit 3 appears at all, it appears 3 times. Also the eight 3-digit numbers formed from the rows, columns (top to bottom) and two diagonals (also top to bottom) must all be different.
Also, the sum of the nine digits used cannot itself be written using the digits you've included in the array.
What is that sum of these nine digits?
(In reply to re: A possible solution
IMHO, the problem did not enforce using none of the digits.
There might be some ambiguity, but the assumption that a solution exists caused my interpretation: do not use all the digits includ4ed in the matrix