10. [Maximum mark: 3'] A set of positive integers {1, 2, 3 , 4, 5, 6, I", 8, 9} is used to form a pack of nine cards. Each card displays one positive integer without repetition from this set. Grace wishes to select four cards at random from this pack of nine cards. (a) Find the number of selections Grace could make if the largest integer drawn among the four cards is either a 5, a 6 or a T. [3] (b) Find the number of selections Grace could make if at least two of the four integers drawn are even. [41