Use the definition of a conditional probability.
P(A|B) = 0.8
P(B|A) = 0.5
P(AuB) = 0.9
Find P(A) and P(B).
I've done many questions like this, however they have some substantial data in them and it's easy to get the general feel on how to solve them. This question however I cannot solve at all.
My biggest problem is that I do not understand what to do with P(AuB) if I dont know weather P(A) and P(B) are independent events; P(AuB) = P(A)*P(B). How do I solve this without that assumption? I have no laws about it in my book and the three I do have just gets me in a circle and back to nothing. Please help!