Possibly the homework numbers differ in the different textbooks due to a publishing error.  Click here to see a more complete description.

1.5
8,9

2.1
1,2,3,5

2.2
4,5,6,7,11,14

2.3
2,3,5,15,17

2.4
3,7,8,10

2.5
1, 4 (unnumbered, but titled "mystery")

6.2
1,2,4