試題詳解

265. A health insurer sells policies to residents of territory X and territory Y. Past claims experience indicates the following:
i) 20% of the total policyholders from territory X and territory Y combined filed no claims.
ii) 15% of the policyholders from territory X filed no claims.
iii) 40% of the policyholders from territory Y filed no claims.
Calculate the probability that a randomly selected policyholder was a resident of territory X, given that the policyholder filed no claims.
(A) 0.09
(B) 0.27
(C) 0.50
(D) 0.60
(E) 0.80