A project comprises the activities shown in the Table below, which also shows the duration of each activity.

Table 2: Activities and duration of project

			Duration in weeks
Activity	Preceding activity	Optimistic	Most likely	Pessimistic
A	-	2	3	3
B	-	10	12	15
C	A	4	5	8
D	B	2	2	2
E	A,D	3	3	3
F	B	3	4	5
G	C,E,F	8	10	20
H	G	2	3	5
I	G	2	2	2
J	H	4	5	10
K	I,J	2	4	6

Construct a network diagram for this project.

Calculate the expected completion tine and variance of all activities.

Determine the critical paths and all critical activities.

Determine the probability that the project will take less than 42 weeks.