The cost and schedule data for a building project are detailed in the following table. Assume an indirect cost $900 per da. What is the optimum (least cost) duration for the project?

Activity	Preceded By	Cost	Duration
Crash	Normal	Crash	Normal
A	-	3,100	2,500	5	6
B	-	8,200	7,000	7	10
C	B	7,000	6,500	5	6
D	-	11,800	10,000	10	12
E	A	5,700	4,200	9	12
F	C, D	8,500	8,200	5	6
G	E,F	6,000	5,200	4	5
H	C,D	8,700	7,500	5	8
I	G,H	6,000	5,600	3	4