Since Sam has fewer number of baseball cards than Jill who has 36 baseball cards and can arrange all his cards in only three ways, the possible number of baseball cards that Sam could have is 27, 30 or 33.
If he has 27 baseball cards, he can arrange 9 baseball cards per row in 3 rows
If he has 30 baseball cards, he can arrange 10 baseball cards per row in 3 rows
If he has 33 baseball cards, he can arrange 11 baseball cards per row in 3 rows
