Solution:
Remember the following formula :
P(AUB) = P(A)+P(B)-P(AnB)
According to the data of the problem and applying the previous equation, we obtain the following equality:
[tex]\frac{4}{9}=\frac{1}{3}+\frac{2}{9}-\text{ P(A n B)}[/tex]
This is equivalent to:
[tex]\frac{4}{9}=\frac{5}{9}-\text{ P(A n B)}[/tex]
solving for P(A n B), we get:
[tex]\text{ P(A n B )= }\frac{5}{9}-\frac{4}{9}=\frac{1}{9}[/tex]
so that, we can conclude that the correct answer is:
[tex]\frac{1}{9}[/tex]
