Section	Problems
2.1	12, 21, 27, 34, 39, 42
2.2	4, 9, 16, 30, 32
2.3	2, 6, 12, 22, 36
2.4	6, 14, 21, 40
2.5	2, 10, 22
2.6	4, 16, 20, 28