please i need help in solving this problems.

7. 'Consider randomly selecting a student at a certain university. and let A denote the event that the selected individual has a Visa credit card and B be the analogous event for MasterCard. Suppose that P(A) = 0.5, P(B) = 0.4, and P(A n B) = 0.3. Calculate and interpret each of the following probabilities. P(3 | A) P(--3 | A) HA I 3) P("I't | 3) Given that the selected individual has at least one card. what is the probability that he or she has a Visa card? ls having a Visa credit card and a MasterCard independent? Justify your answer. 99-9?!\" 1" " Modem Mathematical Statistics with Applications. Devon. I. and Beth K.. Thomson (INT). Chapter 2 8. A certain company sends 50% of its overnight mail parcels via express mail service E1. of these parcels, 1% arrive after the guaranteed delivery time (denote the event late delivery by L). Suppose that 10% of the overnight parcels are sent via express mail service E2 and the remaining 40% are sent via E3. Of those sent via EZ only 2% arrive late, whereas 5% of the parcels handled by E3 arrive late. a. Draw a tree diagram for this problem. b. If a record of an overnight mailing is randomly selected from the company's le, what is the probability that the parcel went via E2 and was late?I c. What is the probability that a randomly selected parcel arrived on time? d. If a randomly selected parcel has arrived late. what is the probability that is was not sent via El '3