Question

Consider a PERT network for a project involving six tasks (a to f)

Task	Predecessor	Expected task time (in days)	Variance of the task time (in days${}^2$)
a	-	30	25
b	a	40	64
c	a	60	81
d	b	25	9
e	b, c	45	36
f	d, e	20	9

The expected completion time of the project is

• A. 238 days
• B. 224 days
• C. 171 days
• D. 155 days

Answer 1

The correct option is D 155 days

PERT networks are:



Here we see that expected completion time of the project is 155 days and critical path is a-c-e-f