Whats is the probability of A AND B occurring when A and B are not mutually exclusive (For mutually exclusive A AND B is impossible).
Please not that I'm asking AND and not A OR B (for mutually non-exclusive events the probablity of A OR B is P(A)+P(B)-P(A AND B) )

I can just algebrically re arrange the last equation and find P(A AND B ) from it, however. I'd like to know if there's alreayd a formula for that.

Question

Whats is the probability of A AND B occurring when A and B are not mutually exclusive (For mutually exclusive A AND B is impossible).
Please not that I'm asking AND and not A OR B (for mutually non-exclusive events the probablity of A OR B is P(A)+P(B)-P(A AND B) ) 

I can just algebrically re arrange the last equation and find P(A AND B ) from it, however. I'd like to know if there's alreayd a formula for that.

phi · Answer

as far as I know, 
P(A and B) = P(A) + P(B) - P(A or B)
which (as you point out), your formula re-arranged