Consider the network described in the table below. Time in weeks.

Activity	Immediate Predecessor(s)	Pessimistic	Probable	Optimistic
J	--	15	10	8
K	--	9	8	6
L	J	10	6	5
M	J	3	3	4
N	K,M	9	5	2
O	K,M	12	7	5
P	L,N	10	8	3

(a) Calculate the expected duration of each activity.

(b) Calculate the expected duration and variance of the critical path.

(c) Calculate the probability that the project will be completed in more than 26 weeks time? How about 30 weeks?