Question 163
Find all pairs of positive integers $A$ and $B$, having the same number of digits in the decimal representation, such that $2 \cdot A \cdot B = \overline{AB}$.
Here $\overline{AB}$ denotes the number obtained by concatenating $A$ and $B$.
Here $\overline{AB}$ denotes the number obtained by concatenating $A$ and $B$.