total deliveries she should have made = 20
Deliveries she has completed = 12
percentage of her completed deliveries can be computed below
[tex]\begin{gathered} \text{ \% completed=}\frac{12}{20}\times100 \\ \text{ \% completed}=\frac{1200}{20} \\ \text{ \% completed}=60\text{ \%} \end{gathered}[/tex]She has completed 60% of her deliveries.