If P(A∩B)=0P(A \cap B) = 0P(A∩B)=0 and P(A∪B)=0.7P(A \cup B) = 0.7P(A∪B)=0.7, what is P(Ac∩Bc)P(A^c \cap B^c)P(Ac∩Bc)?
0.3
0.7
0.49
0.21