Question 9
Find, reasonably, two positive integers $a$ and $b$, such that $$
\begin{aligned}
& b^{2} \text{ be a multiple of } a, \\
& a^{3} \text{ be a multiple of } b^{2}, \\
& b^{4} \text{ be a multiple of } a^{3}, \\
& a^{5} \text{ be a multiple of } b^{4}, \\
& \text{but } b^{6} \text{ Don't be a multiple of } a^{5}.
\end{aligned}
$$
\begin{aligned}
& b^{2} \text{ be a multiple of } a, \\
& a^{3} \text{ be a multiple of } b^{2}, \\
& b^{4} \text{ be a multiple of } a^{3}, \\
& a^{5} \text{ be a multiple of } b^{4}, \\
& \text{but } b^{6} \text{ Don't be a multiple of } a^{5}.
\end{aligned}
$$