1. The problem statement, all variables and given/known data I've attached both the problems into one image to make life easier since problem 1 has a diagram and the other does not. 2. Relevant equations Bayes Theorem : P(A|B)P(B) / [P(A|B)P(B) + P(A|B')P(B')] B' = B Complement 3. The attempt at a solution well for the first one i dont understand what the P(A|B') is and the .849 is that referring to B'? SO i did .001(.05) / [(.001(.05)) + P(A|B')(.849)] i dont know what that P(A|B') is so im not sure where to go from there and the answer in the back of the book says .0099 for the 2nd problem a.) i understand dont need help b.) i dont know how to get P(AB) given the information provided c.) well i can get this if i know part b since it would be .4 + .25 - P(AB) thank u for ur help!