е) $$5\frac{3}{7} : 3 = \frac{38}{7} : \frac{3}{1} = \frac{38}{7} \cdot \frac{1}{3} = \frac{38 \cdot 1}{7 \cdot 3} = \frac{38}{21} = 1\frac{17}{21}$$
Ответ: $$1\frac{17}{21}$$