Вычислите: a) $5 : \frac{2}{3}$; б) $\frac{3}{8} : \frac{1}{3}$; в) $\frac{1}{12} : \frac{5}{36}$; г) $\frac{14}{55} : \frac{5}{21}$; д) $\frac{121}{234} : \frac{11}{12}$

a) $5 : \frac{2}{3} = 5 \cdot \frac{3}{2} = \frac{15}{2} = 7\frac{1}{2}$; б) $\frac{3}{8} : \frac{1}{3} = \frac{3}{8} \cdot \frac{3}{1} = \frac{9}{8} = 1\frac{1}{8}$; в) $\frac{1}{12} : \frac{5}{36} = \frac{1}{12} \cdot \frac{36}{5} = \frac{36}{60} = \frac{3}{5}$; г) $\frac{14}{55} : \frac{5}{21} = \frac{14}{55} \cdot \frac{21}{5} = \frac{294}{275} = 1\frac{19}{275}$; д) $\frac{121}{234} : \frac{11}{12} = \frac{121}{234} \cdot \frac{12}{11} = \frac{11}{117} \cdot 6 = \frac{66}{117} = \frac{22}{39}$