A person randomly selected from a population of interest has a probability of 0.01 ...

A person randomly selected from a population of interest has a probability of 0.01 of having disease D.  The probability of symptom S, which may require a diagnostic test to evaluate its presence or absence, is 0.7 in a person known to have D.  The probability of S in a person known not to have D is 0.02.  A patient from this population is found to have symptom S.  What is the probability this patient has disease D?​