We know the probabilities:
[tex]\begin{gathered} P(A)=0.5 \\ P(B)=0.25 \\ P(A\cap B)=0.185 \end{gathered}[/tex]And we have to find:
[tex]P(A\cup B)[/tex]We can calculate it using the expression:
[tex]\begin{gathered} P(A\cup B)=P(A)+P(B)-P(A\cap B) \\ P(A\cup B)=0.5+0.25-0.185 \\ P(A\cup B)=0.565 \end{gathered}[/tex]Answer: P(A or B) = 0.565.
NOTE: We can convert 0.565 in a fraction as:
[tex]0.565=\frac{565}{1000}=\frac{113}{200}[/tex]So 0.565 is equal to 113/200.