Please help me solve a-c

Problem 9-13 (Algorithmic)

Suppose that the following estimates of activity times (in weeks) were provided for the network shown below:

Activity	Optimistic	Most Probable	Pessimistic
A	3	4	5
B	1.5	2	2.5
C	7	8	9
D	4.5	5	7
E	3	6	9
F	1	2	3
G	9	11	13
H	8	9	16

Assume that the critical pass is A-C-H. Based only on the critical path, what is the estimated probability that the project will be completed. If required, round your answers to two decimal places.

1. Within 21 weeks? fill in the blank 1
2. Within 22 weeks? fill in the blank 2
3. Within 25 weeks? fill in the blank 3