A factory is considering the purchase of a machine that can be semi-automatic, automatic or electronic. The data for each machine are given in the following table.

Deciding which machine to buy using a 30% rate

\begin{tabular}{|l|c|c|c|} \hline Machine & Semiautomatic & Automatic & Electronic \\ \hline C (Cost) & 400,000 & 700,000 & 750,000 \\ \hline ACO (Annual cost of operation) & 125,000 & 20,000 & 5,000 \\ \hline R (rescue) & 10,000 & 80,000 & 300,000 \\ \hline K (useful life) & 8 & 4 & 8 \\ \hline \end{tabular}