I need help understanding how to solve this problem step by step.

Suppose two doctors, A and B, test all patients coming into a clinic for syphilis. Let events A⁺= {doctor A makes a positive diagnosis} and B⁺= {doctor B makes a positive diagnosis}. Suppose doctor A diagnoses 10% of all patients as positive, doctor B diagnoses 17% of all patients as positive, and both doctors diagnose 8% of all patients as positive.

a.Are the events A⁺, B⁺independent?

Suppose a patient is referred for further lab tests if either doctor A or B makes a positive diagnosis.

b.What is the probability that a patient will be referred for further lab test?