Answer
$100$
Work Step by Step
$\bf{\text{Solution Outline:}}$
To evaluate the given expression, $
\displaystyle\sum_{i=1}^{20} 5
,$ use the properties of summation.
$\bf{\text{Solution Details:}}$
Using a property of the summation which is given by $\displaystyle\sum_{i=1}^n c=nc,$ the expression above is equivalent to
\begin{array}{l}\require{cancel}
20(5)
\\\\=
100
.\end{array}
