Problems in bold require full solutions. For the rest of the problems, do as many as you can in 30 minutes.

4.1: 2, 4, 9, 10, 18, 19, 24, 25, 26, 32, 34, [36], 40, 42

4.2: 6, 9, 12, 13, 16, 17, 18, [19], 30