\[\boxed{\text{6.245.}}\]
\[\textbf{а)}\ 47,5\ :5 = 9,5\ \]
\[\textbf{б)}\ 2,25\ :9 = 0,25\ \]
\[\textbf{в)}\ 0,54\ :6 = 0,09\ \]
\[\textbf{г)}\ 9,9\ :18 = 0,55\]
\[\textbf{д)}\ 0,9\ :25 = 0,036\ \]
\[\textbf{е)}\ 5,4\ :216 = 0,025\ \]
\[\textbf{ж)}\ 528,2\ :139 = 3,8\ \]
\[\textbf{з)}\ 40,005\ :127 = 0,315\]