please help this probability and statistics questions with clear steps and details , thanks you

(a) The probability for Clara to get a promotion is 0.4. If she gets a promotion, the probability for her to buy a new watch is 0.77 . If she does not get a promotion, the probability for her to buy a new watch is 0.58 . Let be the event that she gets a promotion and be the event that she buys a new watch.

(i) Fill in the probabilities in the tree diagram in the answer script. (4 marks)

(ii) Find the probability that Clara buys a new watch. Correct your answer to 3 decimal places. (4 marks)

(iii) Find the probability that Clara gets a promotion, given that she buys a new watch. Correct your answer to 3 decimal places. (4 marks)

(b) Suppose there are 4 senior staff and 6 junior staff in a department.

(i) If only 2 senior staff and 1 junior staff can receive salary raise, in how many ways can you distribute the salary raises to the staff in the department? (Assume that the salary raise is the same for everyone who receives it.) (4 marks)

(ii) A task force is to be formed with 3 senior staff and 2 junior staff selected from the department. The 5 staff selected will be assigned to 5 different roles in the task force. In how many ways can the task force be formed?