namely how many times does 10 and 5/16 go into 20?
let's firstly convert the mixed fraction to improper fraction and then divide.
[tex]\bf \stackrel{mixed}{10\frac{5}{16}}\implies \cfrac{10\cdot 16+5}{16}\implies \stackrel{improper}{\cfrac{165}{16}} \\\\\\ 20\div \cfrac{165}{16}\implies \cfrac{20}{1}\div \cfrac{165}{16}\implies \cfrac{20}{1}\cdot \cfrac{16}{165}\implies \cfrac{20}{165}\cdot \cfrac{16}{1}\implies \cfrac{4}{33}\cdot 16 \\\\\\ \cfrac{64}{33}\implies 1\frac{31}{33}[/tex]
