probability and statistics

(a) Six people, A, B, C, D, E and F will be arranged into a row. Find the total number of different ways of arranging them in a row subject to both of the following restrictions: [10] A, B, and C are friends and they want to have a friend standing next to him/her E and F are relatives and they want to stand next to each other. (b) Let A and B be 2 events. Assume that P(A) = 0.4, P(B) = 0.3 and P(A U B) = 0.42. Justify if A and B are independent or not. [10]