12-22 Fred Ridgeway has been given the responsibility of managing a training and development program. He knows the earliest start time, the latest start time, and the total costs for each activity. This information is given in the table on the next page. (a) Using earliest start times, determine Fred's total monthly budget. (b) Using latest start times, determine Fred's total monthly budget. \begin{tabular}{|c|c|c|c|c|} \hline ACTIVITY & ES & LS & t & \begin{tabular}{c} TOTAL COST \\ ($1,000s) \\ \end{tabular} \\ \hline A & 0 & 0 & 6 & 10 \\ \hline B & 1 & 4 & 2 & 14 \\ \hline C & 3 & 3 & 7 & 5 \\ \hline D & 4 & 9 & 3 & 6 \\ \hline E & 6 & 6 & 10 & 14 \\ \hlineF & 14 & 15 & 11 & 13 \\ \hline G & 12 & 18 & 2 & 4 \\ \hlineH & 14 & 14 & 11 & 6 \\ \hlineI & 18 & 21 & 6 & 18 \\ \hlineJ & 18 & 19 & 4 & 12 \\ \hline K & 22 & 22 & 14 & 10 \\ \hlineL & 22 & 23 & 8 & 16 \\ \hlineM & 18 & 24 & 6 & 18 \\ \hline \end{tabular}