How would you find p(AlBcomplement)?
Just 1- the probability of b?
Use your definition of conditional probability.
Prob( P|Q)
= prob(P and Q)/prob(Q)
so p(AlBcomplement) = prob(A | not B)
= prob( A and notB)/prob(notB)
Just 1- the probability of b?
Prob( P|Q)
= prob(P and Q)/prob(Q)
so p(AlBcomplement) = prob(A | not B)
= prob( A and notB)/prob(notB)