(8 points] Let {141:}:21 be a Huqucncc of events such that P[A,-] = 1 for all 1' E {1,2, 3, ....} (a) Prove that P [A1 ['1 A2] = 1. (b) Prove that PUT-1 1143;] = 1 for all n E {1,2,3,...}. 1