$4$ of $5$

$...$

$\backslash$table$[[$Activity$,$Preceding,Duration$],[$A$,-,9],[$B$,$A$,2],[$C$,$A$,12],[$D$,$A$,5],[$E$,$B$,6],[$F$,$C$,$ F$,8],[$H$,$D$,3],[$I$,$H$,8],[$J$,$E$,$ I,$6],[$K$,$E$,,2]]$

$4\mathrm{.}1$ Based on the information provided in the table, which activities should the project manager identify as critical?

$4\mathrm{.}2$ How much slack exists for activities A and $F?$

$4\mathrm{.}3$ How long will it take for the Gautrain project to be completed?