Task Immediate predecessor Duration $($days$)$

a $-5$

b a $18$

c a $13$

d b $3$

e b $10$

f c$,$ e $11$

g d$,$ e $4$

h f$,$ g $9$

i h $2$

Do the followings:

a$)$ Draw the precedence diagram

b$)$ Find the critical path using ES$-$EF$-$LF$-$LS algorithm. Show slack on the diagram

c$)$ Determine expected project duration.