Let:
A = Rolling an odd number
B = Rolling a 5
N = Number of possible outcomes
so:
[tex]\begin{gathered} P(A)=\frac{3}{6}=\frac{1}{2} \\ P(B|A)=\frac{P(B\cap A)}{P(A)} \\ \text{Where:} \\ P(B\cap A)=P(A)\cdot P(B) \\ P(B)=\frac{1}{6} \\ so\colon \\ P(B|A)=\frac{\frac{1}{6}\cdot\frac{1}{2}}{\frac{1}{2}}=\frac{1}{6} \end{gathered}[/tex]