Question 12
For integers $a_1,\ldots,a_n\in\{1,2,3,\ldots,9\}$, the notation $\overline{a_1a_2\cdots a_n}$ denotes $10^{n-1}a_1+10^{n-2}a_2+\cdots+10a_{n-1}+a_n$. For example, when $a=2,b=0$, $\overline{ab}$ denotes $20$. Given $\overline{ab}=b^2$ and $\overline{acbc}=(\overline{ba})^2$, find $\overline{abc}$.