help me understand these three questions

Three companies (A, B. and C) are to be ranked first. second. and third in a list of companies with the highest customer satisfaction. Assuming that all sets of rankings are equally likely, what is the probability that Company B will be ranked first?x Your Answer: Answer Question 15 (1 point) A local country club has a membership of 600 and operates facilities that include an 18-hole championship golf course and 12 tennis courts. Before deciding whether to accept new members. the club president would like to know how many members regularly use each facility. A survey of the membership indicates that 58% regularly use the golf course. 55% regularly use the tennis courts, and 30% use both of these facilities regularly. Find the probability that a randomly selected member uses the golf or tennis facilities regularly. Your Answer: Answer Question 16 (1 point} Think of RNA as a linear sequence of four type nucleotide: adenine (A), cytosine {C}, uracil (U), and guanine (G). How many sequences of size 8 are possible using any of the nucleotides at each place of the sequence. Your