$19\mathrm{.}2$ A computer$-$system installation project consists of eight activities. The immediate predecessors and activity times in weeks are shown below.

$\backslash$table$[[$Activity$,$Immediate Predecessor,Activity Time$],[$A$,-,6],[$B$,-,3],[$C$,$A$,2],[$D$,$B$,$ C$,3],[$E$,$C$,$ D$,6],[$F$,$E$,3],[$G$,$B$,9],[$H$,$F$,$ G$,3]]$

a$.$ Draw the network for this project.

b$.$ Identify the critical path$($s$).$

c$.$ What is the project completion time?