Q1 (5 marks) Let n > 7. There are n (distinct) people who go to a movie and sit next to each other in a row of n adjacent seats. The group of people includes Mike, Kaspian, Theresa, Yunrong and n - 4 others. For each part below, give your answer as a function of n and briefly describe how you obtained it. (a) How many different arrangements of the n people are possible if the four people Mike, Kaspian, Theresa and Yunrong must sit in four consecutive seats and Mike and Kaspian must sit next to each other? (b) How many different arrangements of the n people are possible if among the four people Mike, Kaspian, Theresa and Yunrong, no pair of them can sit next to each other?