3. There are six numbers $a(b+8), b(a+8), a b, a(a+8)$, $b(b+8),(a+8)(b+8)$ for any pair of natural numbers $a$ and $b, a \neq b$. Among them, for some $a$ and $b$, one can find squares of integers. For which $a$ and $b$ will the number of squares be maximally possible
Answer: three squares when $a=1, b=k^{2}, k \neq 1, k \in Z$.