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 ______

$$\begin{gathered} \text{a b }2 \left(here 2 is in units place ,which is divisible by 2 \right) \\ a+b\text{ can be }4,7,10 \\ \text{ if }a+b=4\text{ then }(a,b)\text{ can be }(1,3)\text{ OR }(3,1)\text{ OR }(2,2) \\ \text{ if }a+b=7\text{ then }(a,b)\text{ can be }(2,5),(5,2),(3,4),(4,3) \\ \text{ if }a+b=10\text{ then }(a,b)\text{ can be }(5,5) \\ 8\text{ such case when }2\text{ is at unit's place.} \\ S\mathrm{imilarly} \mathrm{there} \text{ exist }8\text{ such cases when }4\text{ is at unit's place. } \\ \text{ Total }=16 \end{gathered}$$