ANSWER
1/3
EXPLANATION
If we have a fair die, the probability of rolling any of the numbers is the same. In this case, we want to know the probability of rolling a 3 or a 5, which is the sum of the probabilities of rolling each of these values,
[tex]P(3)=P(5)=\frac{1}{6}[/tex]So,
[tex]P(3or5)=P(3)+P(5)=\frac{1}{6}+\frac{1}{6}=\frac{2}{6}=\frac{1}{3}[/tex]Hence, the probability of rolling a 3 or a 5 is 1/3