\[\boxed{\text{6.257.}}\]
\[\textbf{а)}\ \frac{7}{20} = 0,35 = \frac{35}{100} = 0,35\ \]
\[\textbf{б)}\ \frac{9}{80} = 0,1125\ \ \]
\[\textbf{в)}\ \frac{13}{800} = 0,01625\ \]
\[\textbf{г)}\ \frac{24}{192} = \frac{1}{8} = \frac{125}{1000} = 0,125\]
\[\textbf{д)}\ \frac{28}{224} = \frac{1}{8} = \frac{125}{1000} = 0,125\]
\[\textbf{е)}\ \frac{49}{392} = \frac{1}{8} = \frac{125}{1000} = 0,125\]