Consider the Network Presented in the Following Table

Consider the network presented in the following table. Calculate
a. All possible paths
b. The critical path
c. The slack available at any non-critical points
d. The minimum project duration
$$\begin{array} { | c | c | c | } \hline \text { Task } & \begin{array} { c } \text { Duration } \\\text { (Days) }\end{array} & \begin{array} { c } \text { Immediate } \\\text { Predecessors }\end{array} \\\hline \text { A } & 5 & \text { None } \\\hline \text { B } & 3 & \text { A } \\\hline \text { C } & 4 & \mathrm {~A} \\\hline \text { D } & 2 & \text { C } \\\hline \text { E } & 1 & \text { B, D } \\\hline\end{array}$$