Can you please help me with the problem shown in the attached screenshot?

Simone, Larry, lan, Eduardo, Jim, Tyrone, and Sarah have all been invited to a dinner party. They arrive randomly and each person arrives at a different time. a. In how many ways can they arrive? b. In how many ways can Simone arrive first and Sarah last? c. Find the probability that Simone will arrive first and Sarah last. a. (Type an integer.) b. (Type an integer.) C. (Type a fraction. Simplify your answer.)