[tex]\it n:5=12\ \ rest\ \ r \Rightarrow \begin{cases}\it n=12\cdot5+r \Rightarrow n=60+r\ \ \ \ \ (1)\\ \\ \it r<5\ \ \ \ \ \ (2)\end{cases}\\ \\ \\ (2)\ \Rightarrow r\in\{0,\ 1,\ 2,\ 3,\ 4\}|_{+60}\ \stackrel{(1)}{\Longrightarrow}\ n\in\{60,\ 61,\ 62,\ 63,\ 64\}[/tex]
