$($a$)$ Draw project network using AON method, filling the ES$,$ EF$,$ LS$,$ LF and slack for each node. What is the

critical path$($s$)$ and completion time of the project? $(10$ marks$)$

$($b$)$ Draw the project network using the AOA method. Calculate the earliest time and latest time for each node.

$(8$ marks$)$