(20 marks) Consider the weather conditions in two consecutive days, and let the sample space be = {(R, R), (R, N), (N, R), (N, N)}, where R stands for rain, N stands for no rain, the first element in a pair indicates whether it rains on the first day, and the second element whether it rains on the second day. If the probabilities of the elementary events are given below 3 (R, R) (R,N) (N,R) (N, N) P 1/9 2/9 2/9 4/9 (a) (5 marks) Let A be the event that it rains on the first day, and B be the event that it rains on the second day. Write down A and B as subsets of 2.