It helps to first simplify $\displaystyle\frac{{12}}{{24}}\usepackage{cmbright}\Huge\$ to $\displaystyle\frac{{1}}{{2}}\usepackage{cmbright}\Huge\$ . Finding a common denominator, you can compare $\displaystyle\frac{{8}}{{18}}\usepackage{cmbright}\Huge\$ to $\displaystyle\frac{{9}}{{18}}\usepackage{cmbright}\Huge\$ and see that $\displaystyle\frac{{8}}{{18}}<\frac{{9}}{{18}}\usepackage{cmbright}\Huge\$ , which means $\displaystyle\frac{{4}}{{9}}<\frac{{12}}{{24}}\usepackage{cmbright}\Huge\$ . The correct answer is $\displaystyle\frac{{4}}{{6}}>\frac{{4}}{{9}}\usepackage{cmbright}\Huge\$ .