Already Solved a), just need help with the rest

Problem 10-05 Premier Consulting's two consultants, Avery and Baker, can be scheduled to work for clients up to a maximum of 160 hours each over the next four weeks. A third consultant, Campbell, has some administrative assignments already planned and is available for clients up to a maximum of 140 hours over the next four weeks. The company has four clients with projects in process. The estimated hourly requirements for each of the clients over the four-week period are as follows: Client B D Hours 180 75 100 85 Hourly rates vary for the consultant-client combination and are based on several factors, including project type and the consultant's experience. The rates (dollars per hour) for each consultant-client combination are as follows: Consultant Avery Baker Campbell A 100 120 155 B 125 135 150 Client C 115 115 140 D 100 120 130 a. Choose the correct network representation of the problem. (i) (ii) 100 A 180 180 A 1 1 120 100 155 125 160 Avery Avery 160 115 100 125 75 75 B 2 135 120 135 150 160 Baker 2 115 Baker 2 160 115 120 Om 100 100 C 115 155 3 150 140 140 Campbell 140 Campbell 3 140 120 130 D 85 85 D 4 130 (iii) (iv) 100 180 A 180 1 125 100 120 115 160 Avery Avery 1 160 1 155 125 100 75 75 B 120 135 135 140 Baker 2 150 Baker 2 ! 140 115 115 100 100 C 120 140 155 140 Campbell 100 3 120 150 Campbell 3 140 140 130 D 85 85 D 130 b. Formulate the problem as a linear program, with the optimal solution providing the hours each consultant should be scheduled for each client to maximize the consulting firm's billings. What is the schedule and what is the total billing? Let Xij = number of hours from consultant i assigned to client j. + + Max X11 X12 X 13 X 14 X21 X22 X23 + + + + + X24 X31 X32 X33 X34 s.t. + + + |X11 X12 X13 X 14 + X21 X22 X23 X24 + + + s X31 X32 X33 X34 X11 X21 X31 + X 12 X22 X32 + + = X13 X23 X33 X14 X24 X34 Xij > 0 for all i, j Hours Assigned Billing Avery-Client A Avery-Client B Avery-Client C Avery-Client D Baker-Client A Baker-Client B Baker-Client C Baker-Client D Campbell-Client A Campbell-Client B Campbell-Client C Campbell-Client D Total Billing $ c. New information shows that Avery doesn't have the experience to be scheduled for client B. If this consulting assignment is not permitted, what impact does it have on total billings? What is the revised schedule? Hours Assigned Billing Avery-Client A Avery-Client B Avery-Client C Avery-Client D Baker-Client A Baker-Client B Baker-Client C Baker-Client D Campbell-Client A Campbell-Client B Campbell-Client C Campbell-Client D Total Billing