An art class consists of ten students. All of them must present their portfolios and explain their work to the instructor and their classmates at the end of the semester.(a) If their names are drawn...

An art class consists of ten students. All of them must present their portfolios and explain their work to the instructor and their classmates at the end of the semester.(a) If their names are drawn from a hat to determine who goes first, second, and so on, how many presentation orders are possible?
(b) If their names are put in alphabetical order to determine who goes first, second, and so on, how many presentations orders are possible?