\[\boxed{\text{5.517.}}\]
\[\textbf{а)}\ 6\frac{1}{7} = \frac{43}{7};\ \frac{7}{43}:\]
\[да.\]
\[\textbf{б)}\ 45\ и\ \frac{1}{40}:\]
\[нет.\]
\[\textbf{в)}\ 1\frac{1}{5} = \frac{6}{5};\ \frac{5}{6}:\]
\[да.\]
\[\textbf{г)}\ 0\ и\ 1:\]
\[нет.\]