Total numbers of 3-digit numbers that are divisible by 6 and can be formed by using the digits $1,2,3,4,5$ with repetition, is _________.

A number is divisible by 6 if it is divisible by both 2 and 3. A number is divisible by 2 if its last digit is even, which means it must be either 2 or 4 from the given digits. A number is divisible by 3 if the sum of its digits is divisible by 3. <br/><br/>$$ \begin{aligned} & (2,1,3),(2,3,4),(2,5,5),(2,2,5),(2,2,2) \\\\ & (4,1,1),(4,4,1),(4,4,4),(4,3,5) \\\\ & 2,1,3 \Rightarrow 312,132 \\\\ & 2,3,4 \Rightarrow 342,432,234,324 \\\\ & 2,5,5 \Rightarrow 552 \\\\ & 2,2,5 \Rightarrow 252,522 \\\\ & 2,2,2 \Rightarrow 222 \\\\ & 4,1,1 \Rightarrow 114 \\\\ & 4,4,1 \Rightarrow 414,144 \\\\ & 4,4,4 \Rightarrow 444 \\\\ & 4,3,5 \Rightarrow 354,534 \end{aligned} $$ <br/><br/>Total 16 numbers.