181.1= 49

$$18\frac{1}{4} \cdot \frac{1}{9} = (18 + \frac{1}{4}) \cdot \frac{1}{9} = 18 \cdot \frac{1}{9} + \frac{1}{4} \cdot \frac{1}{9} = 2 + \frac{1}{36} = 2\frac{1}{36}$$

Ответ: $$2\frac{1}{36} $$