25. The purchase price of a Machine \( A \) is \( Rs 0000 \). Its salvage rates \& maintenance costs are as follows. Determine the optimal age of replacement
\begin{tabular}{|c|c|c|c|c|c|}
\hline Age(years) & 1 & 2 & 3 & 4 & 5 \\
\hline Salvage rate (Rs) & \( 5 \sqrt{2}-500 \) & 4000 & 3000 & 2000 & 1000 \\
\hline Maintenance cost(Rs) & 600 & 800 & 1000 & 1400 & 2000 \\
\hline\( C \) C
\end{tabular}