Factors of 30 (from least to greatest): 1, 2, 3, 5, 6, 10, 15, 30
Factors of 30 (from greatest to least): 30, 15, 10, 6, 5, 3, 2, 1
Combining the elements of these two ordered lists, we can group the factors as follows: (1, 30), (2, 15), (3, 10), (5, 6), (6,5), (10, 3), (15, 2), (30, 1)