Hello! I got the answers for (e) = 0.6

Question 2 (a)(i) = 0.2 x 0.2

(ii) = (0.20)^10

(b)(i) = 0.556

(ii) = 0.067

I don't know if they're right and I'm not sure how to get the marks for the working out I did if they are right... Please could you help me :)

(e) If P[A u B] = 0.7 and P(A U E) = 0.9, determine P(A). (6) QUESTION 2 [20 Marks] Chapter 3: Discrete random variables and their probability distributions (a) Almost every retail business has the problem of determining how much inventory to purchase. Insufficient inventory may result in lost business, and excess inventory will have detrimental effect on profit. Suppose that retail computer store owner is planning to replace an order for personal computer (PCs). She is trying to decide how many IBM PCs and how many IBM compatibles (personal computers that run all or most the same software as the IBM PC but that are not manufactured by IBM) to order. The owner's records indicate that 80% of the previous PC customers purchased IBM PCs, and 20% purchased compatibles. (i) What is the probability that next two customers will purchase compatibles? (4) (ii) What is the probability that next ten customers will purchase compatibles? (4) (b) A university has twice as many undergraduate students as graduate students. Twenty five percent of the graduate students live on campus, and 10% of the undergraduate students live on campus. (i) If a student is chosen at random from the student population, what is the probability that the student is an old student living on a campus? (8) (ii) If a student living on a campus is chosen at random, what is the probability that the student is a new student? (4)