Suppose P(A) = .40 and P(B @ A) = .30. What is the joint probability of A and B? 24. Suppose P(X1) = .75 and P(Y2 @ X1) = .40. What is the joint probability of X1 and Y2? 25. A local bank reports that 80 percent of its customers maintain a checking account, 60 per- cent have a savings account, and 50 percent have both. If a customer is chosen at ran- dom, what is the probability the customer has either a checking or a savings account? What is the probability the customer does not have either a checking or a savings account?