Consider the given network:

The data of the normal times, the minimum duration times (crash times) and the reduction costs are given in the following table:

Activities	normal time	minimum time	reduction cost
A	10	7	4
B	5	4	2
C	3	2	2
D	4	3	3
E	5	3	3
F	6	3	5
G	5	2	1
H	6	4	4
I	6	4	3
J	4	3	3

If T represents the minimum completion time of the project: a) Determine the maximum and minimum value of T. b) Write the linear program to solve the CPM problem if the project is to be completed in 21 days at minimal cost. c) Given that the indirect cost is $ 5 per day, determine the optimal duration of the project in terms of the reduction and indirect costs by the direct enumeration method.

J 3 D 5 H E