Given the activity table $($Table of Dependencies$)$ below for a certain project:

$\backslash$table$[[$Activity$,$Predecessor,Duration $($Weeks$)],[$A$,-,1],[$B$,$A$,1],[$C$,$A$,2],[$D$,$A$,3],[$E$,$B$,2],[$F$,$C$,2],[$G$,$E$,3],[$H$,$D$,$F$,$G$,2]]$

a$)$ Calculate the project duration $($using the forward pass$),$ calculate the critical path $($using the backward pass$)(10$ Marks$)$

b$)$ Based on the answers obtained in question a$)$ and the Table of Dependencies; construct a Gantt chart. $(10$ Marks$)$