Question : On a Saturday night, 20% of all drivers in U.S.A. are under the influence of alcohol. The probability that a driver under the influence of alcohol will have an accident is 0.001. The probability that a sober driver will have an accident is 0.0001.If a car on a Saturday night smashed into a tree, the probability that the driver was under the influence of alcohol is
(A) 3/7
(B) 4/7
(C) 5/7
(D) 6/7
Answer : option (C)
Solution :
