In a clinical study, volunteers are tested for a gene that has been found to increase the risk for a disease. The probability that a person carries the gene is 0.2. (a) What is the probability that 4 or more people will have to be tested until 2 of them with the gene are detected? Round your answer to three decimal places (e.g. 0.987). (b) How many people are expected to be tested until 2 of them with the gene are detected?