An IT software project comprises the following activities, whose time estimates are given against each other as below:

Activity	Estimated Duration (weeks)
-	Optimistic	Most Likely	Pessimistic
1-2	3	6	15
1-3	2	5	14
1-4	6	12	30
2-5	2	5	8
2-6	5	11	17
3-6	3	6	15
4-7	3	9	27
5-7	1	4	7
6-7	4	19	28

a) Find the critical path for the project. (10 marks)

b) Whatis the expected project duration? (10 marks)