Discrete Math : Subsets and Elements

Let S = {1,2,3,4,5,6,7,8}. Determine:

(a) The number of subsets of S

(b) The number of subsets of S with at most four elements

(c) The number of ordered lists with elements chosen form S (with possible repititions)

(d) The number of ordered lists with nine elements chosen form S with no repititions

(e) The number of element multisets chosen from S.