$(3$ marks$)$

c$)$ A project consists of seven activities $A,B,C,D,E,F,G.$ The precedence relationships and time estimates are as follows:

$\backslash$table$[[$Job precedence,Duration in weeks$],[$A$,,2,5,8],[$B$,$A$,6,9,12],[$C$,$A$,5,14,17]]$

$2$

$\backslash$table$[[$D$,$B$,5,8,11],[$E$,$GD$,3,6,9],[$F$,-,3,12,21],[$G$,$EF$,1,4,7]]$

ii$)$ Determine the expected job duration and variance of each job. $(5$ marks$)q,$

iii$)$ What is the expected length of the project and its variance?

$(4$ marks$)$