KöMaL 2012 K319

$a$) What digits are denoted by $a$, and by $b$ if $\overline{2a6} +158=\overline{3b4}$ is divisible by 3? $b$) What may $c$ and $d$ be if $\overline{2c6} +118=\overline{4d4}$ is divisible by 4?