A Project Is Composed of the Twelve Activities Shown in the Table

Essay

A project is composed of the twelve activities shown in the table. What are the earliest and latest start times for each of these activities?
$$\begin{array} { | c | c | c | } \hline \text { Activity } & \text { Time (days) } & \text { Predecessors } \\\hline \text { A } & 3 & \cdots \\\hline \text { B } & 3 & \text { A } \\\hline \text { C } & 15 & \text { A } \\\hline \text { D } & 2 & \text { B } \\\hline \text { E } & 12 & \text { B } \\\hline \text { F } & 16 & \text { C } \\\hline \text { G } & 2 & \text { C } \\\hline \text { H } & 11 & \text { E, F } \\\hline \text { I } & 9 & \text { D, G } \\\hline \text { J } & 6 & \text { D, E } \\\hline \text { K } & 15 & \text { H, I } \\\hline \text { L } & 13 & \text { J, K } \\\hline\end{array}$$