if P(A^c)=80% , then P(A and A^c) is equal to?

Question

Statistics and probability. 

Answer 1

P(A^c) =P(A and c) = P(A and A^c) = Probability of A and c

In a Venn diagram, it's where the two circles overlap.

P(A^c) = P(A^A^c) = probability of A + probability of c - probability of (A or c)

= P(A) + P(c) - P(Avc)

P(Avc) = P(A) + P(c) - P(A^c)