\[\boxed{\text{5.225.}}\]
\[\ \frac{6}{n}\ (м) - длина\ одной\ части\ \]
\[бревна.\ \]
\[n = 1:\ \ \ \ \ \]
\[\frac{6}{1} = 6\ м;\ \]
\[n = 2:\ \ \ \ \ \ \]
\[\frac{6}{2} = 3\ м;\ \]
\[n = 3:\ \ \ \ \ \ \]
\[\frac{6}{3} = 2\ м.\ \]