19. In how many ways can the eight members of a student council pose in a line for a yearbook photo graph if the chair and vice chair must not be side-by-side? Explain your reasoning. 20. The group organizing the Statesville college reunion includes six current students, eight current staff members, and 11 Alumni. Two individuals from each category were work on the publicity committee. Use combinations to determine the number of different publicity committees the group could form. 21. Kelly lives in a subdivision where the streets are laid out in a grid pattern. Her school is six blocks south and five blocks east of her home. How many different direct routes could she take when the bicycles to school if she always stops by her friends home, which is three Blocks south and two blocks east of Kelly's home. Explain your reasoning and draw