[tex]P(A \cap B) = P(A) \cdot P(B)[/tex]
so
[tex]P(A) = \frac{P(A \cap B)}{P(B)} = \frac{2/3}{3/4} = \frac{8}{9}[/tex]
also, if A or B happens but not both, you add the chances and subtract the chance that both are happening.
[tex]P(A|B) = P(A) + P(B) - P(A \cap B) = \frac{8}{9} +\frac{3}{4} - \frac{2}{3} = \frac{35}{36}[/tex]
