In general, the probability of a disjunction is
[tex]P(A \lor B) = P(A)+P(B)-P(A\cap B)[/tex]
In this case, A and B are mutually exclusive, so [tex]P(A\cap B)=0[/tex]
This simplifies the formula to
[tex]P(A \lor B) = P(A)+P(B) = 0.22+0.46 = 0.68[/tex]