23. Given that $x=2 a^{5}=3 b^{2}$ where $a$ and $b$ are positive integers, find the least possible value of $x$.
23 Ans: 15552 .
Observe that $3 \mid a$ and $2 \mid b$. Set $b=2 b$. Then we see that $2 \mid a$. Thus the smallest possible value of $a$ is 6 . Hence $x=2\left(6^{5}\right)=15552$.