27,4:18,3

To simplify the expression \( \frac{27}{4} : \frac{18}{3} \), we need to divide the fractions by multiplying by the reciprocal of the second fraction.

So, it becomes:

\[ \frac{27}{4} \times \frac{3}{18} \]

Now, calculate it:

\[ \frac{27}{4} \times \frac{3}{18} = \frac{81}{72} = \frac{9}{8} \]

Therefore, the simplified expression is \( \frac{9}{8} \).