1. The problem statement, all variables and given/known data A president, treasurer, and secretary, all different, are to be chosen from among the 10 active members of a university club. How many different choices are possible if: a) There are no restrictions. b) A will serve only if she is the treasurer. c) B and C will not serve together. d) D and E will serve together or not at all. e) F must be an officer. 2. Relevant equations N/A 3. The attempt at a solution For part (a): 720 combinations. For part (b): 72 combinations. For part (c): 448 combinations. For part (d): 8 combinations. For part (e): 72 combinations. Are any of these answers correct? I am wary about the answer for part (d), but please let me know which ones might be wrong and I will explain my methodology. Thanks!