Professor, I'm not quite getting the constraints properly. Please correct my understanding, and forgive me for appearing to overlook some of your responses so far, as I can't get my understanding of all of them to jibe.
We seek a magic square with 9 baskets, all different positive numbers of apples. (Magic square: all rows, all columns, and both major diagonals add to the same number of apples)
1) No matter what size tour came through, the Professor could not find a basket that could be shared equally by the number of students
2) Tour size >1
3) share size > 1