16.
In the given triangles,
[tex]\begin{gathered} \angle JLK=\angle PLM\text{ (Vertically Opposite Angle)} \\ \angle LJK=\angle LPM\text{ (Given)} \end{gathered}[/tex]Hence form AA critesion,
[tex]\Delta JLK\approx\Delta PLM[/tex]From the property of similar triangles,
[tex]\begin{gathered} \frac{JK}{PM}=\frac{JL}{PL} \\ \Rightarrow\frac{x}{12}=\frac{4}{6} \\ \Rightarrow x=8 \end{gathered}[/tex]Thus, the requried value of JK is 8.