Probability for dependent events and "Or" Is there a way to calculate the "or" of dependent events?
That is if P(A) = 0.25 and P(B) = 0.6
and P(A|B) = 0 and P(B|A) = 0
I know I can calculate P(A and B) = P(A|B) * P(B)
Is there some way to calculate P(A or B)? 

$$P(A \text{ or } B) = P(A) + P(B) - P(A \text{ and } B)$$
And you know how to get $P(A \text{ and } B)$.
