Answer :
[tex]\begin{gathered} \frac{y^6}{8y^3}=\frac{y^6}{y^3}\times\frac{1}{8} \\ =\frac{1}{8}\times y^{6-3} \\ =\frac{1}{8}\times y^3 \\ =\frac{y^3}{8} \end{gathered}[/tex]
Thus, the simplest form is y³/8.