A certain virus infects one in every 200 people. A test used to detect the virus in a person is positive 80% of the time if the person has the virus and 5% of the time if the person does not have the virus. Let A be the event "the person is infected" and B be the event "the person tests positive.

using bayes theorem when a person tests positive, determine the probability that a person is infected

using bayes theorem when a person tests negative, determine the probability that a person is not infected