Answer
$ a.\quad$Improper fraction:$\displaystyle \quad\frac{11}{2}.$
$ b.\quad$Mixed number:$\displaystyle \quad 5\frac{1}{2}$
Work Step by Step
Each object is divided into $2$ equal parts.
Each part represents $\displaystyle \frac{1}{2}$ of the object.
Eleven parts in all are shaded, or $\displaystyle \frac{11}{2}$.
As a mixed number, we have 5 whole objects and $\displaystyle \frac{1}{2}$ of the last one...or, $5\displaystyle \frac{1}{2}$ .
( Dividing $11\div 2,$ quotient = $5$, remainder $1,$ so $\displaystyle \frac{11}{2}=5\frac{1}{2}$ )