Answer:LetAbe the event that the person is taking the drug. We are told thatP(A) = 0.05.LetBbe the event that the person has migraines. We are told thatP(B) = 0.1.Further, we are told thatP(B|A) = 0.3. Using the rules for conditional probability,P(A|B) =P(A∩B)P(B)=P(B|A)P(A)P(B)=0.3·0.050.1=0.15.The probability that a migraine sufferer takes the drug is 15%.
