\[5 : \frac{2}{3} = \frac{5}{1} \cdot \frac{3}{2} = \frac{5 \cdot 3}{1 \cdot 2} = \frac{15}{2} = 7\frac{1}{2}\]
\[\frac{3}{8} : \frac{1}{3} = \frac{3}{8} \cdot \frac{3}{1} = \frac{3 \cdot 3}{8 \cdot 1} = \frac{9}{8} = 1\frac{1}{8}\]
\[\frac{1}{12} : \frac{5}{36} = \frac{1}{12} \cdot \frac{36}{5} = \frac{1 \cdot 36}{12 \cdot 5} = \frac{1 \cdot 3}{1 \cdot 5} = \frac{3}{5}\]
\[\frac{14}{55} : \frac{5}{21} = \frac{14}{55} \cdot \frac{21}{5} = \frac{14 \cdot 21}{55 \cdot 5} = \frac{294}{275} = 1\frac{19}{275}\]
\[\frac{121}{8} : \frac{5}{8} = \frac{121}{8} \cdot \frac{8}{5} = \frac{121 \cdot 8}{8 \cdot 5} = \frac{121}{5} = 24\frac{1}{5}\]
Ответ: a) 7 1/2; б) 1 1/8; в) 3/5; г) 1 19/275; д) 24 1/5