The probability that events A or B occur is the probability of the union of A and B.
Similarly, the probability that events A and B occur is the probability of the intersection of A and B.
The probability of the union of two events is:
[tex]P(A\cup B)=P(A)+P(B)-P(A\cap B)[/tex]In this case, we have:
[tex]P(\text{blonde or green eyes})=P(\text{blonde})+P(\text{green eyes})-P(\text{blonde and green eyes})[/tex][tex]\begin{gathered} P(\text{blonde})=50\text{\% }=\frac{50}{100}=0.5 \\ P(\text{green eyes})=10\text{\% }=\frac{10}{100}=0.1 \\ P(\text{blonde and green eyes})=3\text{\% }=\frac{3}{100}=0.03 \\ P(\text{blonde or green eyes})=P(\text{blonde})+P(\text{green eyes})-P(\text{blonde and green eyes}) \\ P(\text{blonde or green eyes})=0.5+0.1+0.03 \\ P(\text{blonde or green eyes})=0.57 \end{gathered}[/tex]Therefore, the probability that a student selected will be blonde or have green eyes is 0.57 or 57%.
