試題詳解

20. Upon arrival at a hospital’s emergency room, patients are categorized according to their condition as critical, serious, or stable. In the past year:
(i) 10% of the emergency room patients were critical；
(ii) 30% of the emergency room patients were serious；
(iii) the rest of the emergency room patients were stable；
(iv) 40% of the critical patients died；
(vi) 10% of the serious patients died； and
(vii) 1% of the stable patients died.
Given that a patient survived, calculate the probability that the patient was categorized as serious upon arrival.
(A) 0.06
(B) 0.29
(C) 0.30
(D) 0.39
(E) 0.64