i. $\frac{2}{3} \div \frac{1}{4}$
ii. $\frac{5}{9} \div \frac{3}{2}$
iii. $\frac{3}{7} \div \frac{5}{11}$
iv. $\frac{11}{12} \div \frac{4}{7}$
$\frac{2}{3} \div \frac{1}{4}=\frac{2}{3} \times \frac{4}{1}=\frac{2 \times 4}{3 \times 1}=\frac{8}{3}$
$\begin{aligned} & \text { ii. } \frac{5}{9} \div \frac{3}{2} \\ & \frac{5}{9} \div \frac{3}{2}=\frac{5}{9} \times \frac{2}{3}=\frac{5 \times 2}{9 \times 3}=\frac{10}{27}\end{aligned}$
$\begin{aligned} & \text { iii. } \frac{3}{7} \div \frac{5}{11} \\ & \frac{3}{7} \div \frac{5}{11}=\frac{3}{7} \times \frac{11}{5}=\frac{3 \times 11}{7 \times 5}=\frac{33}{35}\end{aligned}$
$\begin{aligned} & \text { iv. } \frac{11}{12} \div \frac{4}{7} \\ & \frac{11}{12} \div \frac{4}{7}=\frac{11}{12} \times \frac{7}{4}=\frac{11 \times 7}{12 \times 4}=\frac{77}{48}\end{aligned}$