According to recent estimates, only 45 % of people in Africa have access to safe drinking water, this being the major cause of many waterborne diseases. The incidence rate of waterborne diseases in communities which do not have access to safe drinking water is 88 %, whereas in communities which do have access to safe drinking water, this rate is 22 %.
(a) What is the incidence rate of waterborne diseases in Africa?
(b) A patient suffering from a waterborne disease is randomly chosen from a clinic in an African village. What is the probability that this patient did not have access tosafe drinking water?