1 1/5 : 1,6-4/5•0,125

To simplify the expression, we first need to convert the fractions to a common denominator:

\[ \frac{1}{5} = \frac{1}{5} \]

\[ \frac{4}{5} = \frac{4 \times 25}{5 \times 25} = \frac{100}{25} = \frac{4}{1} \]

Now we can rewrite the expression:

\[ 1 \frac{1}{5} : 1,6 - \frac{4}{5} \cdot 0,125 \]

\[ = 1 + \frac{1}{5} : 1 + \frac{6}{10} - \frac{4}{1} \cdot \frac{1}{8} \]

\[ = 1 + \frac{1}{5} : 1 + \frac{6}{10} - \frac{4}{8} \]

\[ = 1 + \frac{1}{5} : 1 + 0.6 - 0.5 \]

\[ = 1 + \frac{1}{5} : 1 + 0.6 - 0.5 \]

To divide by a fraction, we multiply by the reciprocal:

\[ = 1 + \frac{1}{5} \times \frac{1}{1} + 0.6 - 0.5 \]

\[ = 1 + \frac{1}{5} + 0.6 - 0.5 \]

\[ = 1 + 0.2 + 0.6 - 0.5 \]

\[ = 1.7 \]

Therefore, \( 1 \frac{1}{5} : 1,6 - 4/5 \cdot 0,125 \) simplifies to 1.7.