let's firstly convert the mixed fraction to improper fraction, and then divide.
[tex]\bf \stackrel{mixed}{11\frac{1}{2}}\implies \cfrac{11\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{23}{2}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{23}{2}\div \cfrac{3}{4}\implies \cfrac{23}{2}\cdot \cfrac{4}{3}\implies \cfrac{23}{3}\cdot \cfrac{4}{2}\implies \cfrac{23}{3}\cdot 2\implies \cfrac{46}{3}\implies 15\frac{1}{3}[/tex]
