Section 2.5 (problems 2.5.x): 2, 3, 5, 6 (refer to Appendix A, rather than deriving from scratch), and 9.
Section 2.6: 1 and 2.
Section 2.7: 2, 7 (state answer for all possible values of k), and 8 (you should be able to do parts (a) and (b), and give your best effort on part (c)).
Problem 2.5.9: Will Woods and Pete James
Problem 2.7.7: Jeff Arcara and Jeff Dicicco
Problem 2.7.8: Paul Holencik and Katie Souza