\[\boxed{\text{286\ (286).}\text{\ }\text{Еуроки\ -\ ДЗ\ без\ мороки}}\]
\[m^{3}n^{2} = 3;\ \ \frac{1}{3}n^{3}p^{2} = 5;\ \ n^{3}p^{2} =\]
\[= 15\]
\[1)\ m^{3}n^{5}p^{2} = m^{3}n^{2} \cdot n^{3}p^{2} =\]
\[= 3 \cdot 15 = 45\]
\[2)\ 2m^{3}n^{8}p^{4} = 2 \cdot m^{3}n^{2} \cdot n^{6}p^{4} =\]
\[= 2 \cdot 3 \cdot \left( n^{3}p^{2} \right)^{2} = 6 \cdot 15^{2} =\]
\[= 6 \cdot 225 = 1350\]
\[3) - 0,4m^{12}n^{11}p^{2} =\]
\[= - \frac{2}{5} \cdot n^{3}p^{2} \cdot m^{12}n^{8} =\]
\[= - \frac{2}{5} \cdot 15 \cdot \left( m^{3}n^{2} \right)^{4} =\]
\[= - 6 \cdot 3^{4} = - 6 \cdot 81 = - 486\]