4) A simple network has three activities, A, B, and C. A is an immediate predecessor of B and of C. B is an immediate predecessor of C. The activity durations are A = 4, B = 3,C= 8. a) The critical path is A-C, duration 12. b) The critical path is A-B-C, duration 15. c) The critical path is A-B, duration 7. d) The critical path cannot be determined. e) The network has no critical path. 5) Which of the following statements about the basic EOQ modelis true? a) If the ordering cost were to double, the EOQ would rise. b) If annual demand were to double, the EOQ would increase. c) If the carrying cost were to increase, the EOQ would fall. d) If annual demand were to double, the number of orders per year would increase. e) All of the above statements are true. 6) A company has an arrival rate 12.6/hour and it takes 20 minutes to serve a customer. With 6 servers, what is the probability that no customers are waiting? I a) 13% b) 4.9% c) 1.3% d) 4.2% e) 30%