The University President Concocts a Thirteen-Step Sinister Plan to Lower

The university president concocts a thirteen-step sinister plan to lower morale to zero during his last year in office. The duration of each step (in days)and the required predecessor(s)are displayed in the table.
$$\begin{array} { | l | l | l | } \hline \text { Activity } & \text { Duration } & \text { Predecessor } \\\hline \text { A } & 3 & - \\\hline B & 8 & - \\\hline \mathrm { B } & 8 & \text { A } \\\hline \mathrm { D } & 7 & \text { B } \\\hline \mathrm { E } & 4 & \mathrm {~B} \\\hline \mathrm { F } & 4 & \mathrm { C } , \mathrm { D } \\\hline \mathrm { G } & \mathrm { B } & \mathrm { C } , \mathrm { D } \\\hline \mathrm { H } & 8 & \mathrm { E } \\\hline \mathrm { I } & 8 & \mathrm {~F} \\\hline \mathrm { K } & 4 & \mathrm { G } \\\hline \mathrm { K } & 2 & \mathrm { H } \\\hline \mathrm { L } & 6 & \mathrm { I } \\\hline \mathrm { M } & 10 & \text { I, K } \\\hline\end{array}$$
-Identify the activities that have slack and the amount of slack each has for this morale-lowering project?