let \(\displaystyle{X}_{{{i}}}\); be the random variable for site A.

Construct a payoff table:

\(\begin{array}{|c|c|}\hline x_{i}&$30&-$3\\ \hline p_{i}&0.2&0.8\\ \hline\end{array}\)

Determine the expected value using formula \(\displaystyle{E}{\left({X}\right)}={x}\cdot{p}{\left({x}\right)}\)

\(\displaystyle{E}{\left({X}\right)}={20}{\left({0.2}\right)}-{3}{\left({0.8}\right)}\)

\(\displaystyle={4}-{2.4}\)

\(\displaystyle={1.6}\)

Therefore the expected value is 1.6.