Question 3 (25 marks) The table below indicates the precedence requirements, activity times, and normal and crash costs for a construction project.

Activity	Precedes	Normal Time (weeks)	Normal Cost	Crashing Cost ($ per week) Can crash activities 1 or 2 weeks;
				First Week	Second Week
A	B, C	5	$7,000	$1200	$1200
B	D	4	5000	1000	1000
C	E, F	3	4000	1000	-
D	G, H	6	10,000	1100	-
E	H	4	9000	500	500
F	H	5	7000	750	750
G	I	4	9,000	1200	1200
H	I, J	5	8,000	1200	1200
I	End	5	10,000	1500	1500
J	End	6	6,000	1200	-

1. Which activities have slack, and how much? What paths have slack and how much? (5 marks)
2. Determine the minimum-cost crashing schedule that will reduce the total length of the project by five weeks; which activities should you shorten (crash) and by how much. What is the critical path after crashing and how much slack does each path have now. (7 marks)