4:16 41

$${\frac{4}{41}} : 16 = {\frac{4}{41}} \cdot {\frac{1}{16}} = {\frac{4}{41 \cdot 16}} = {\frac{4}{41 \cdot 4 \cdot 4}} = {\frac{1}{41 \cdot 4}} = {\frac{1}{164}}$$

Ответ: $$\frac{1}{164}$$