Question 22
$\overline{abc}$ is a 3-digit number with no repeated digits.
$$\overline{ab}+\overline{ba}+\overline{ac}+\overline{ca}+\overline{bc}+\overline{cb}=\overline{abc}.$$
Given that the sum of digits of $\overline{abc}$ are multiples of ___.
Source wording note: the Vietnamese line instead asks to find the sum of the digits.
$$\overline{ab}+\overline{ba}+\overline{ac}+\overline{ca}+\overline{bc}+\overline{cb}=\overline{abc}.$$
Given that the sum of digits of $\overline{abc}$ are multiples of ___.
Source wording note: the Vietnamese line instead asks to find the sum of the digits.