8. An agent serves a customer for 5 minutes on average, and the standard deviation of the processing time is 1.2 minutes. The demand rate is 10 customers/hour, and the coefficient of variation of the arrival process is 0.3. Assume that there is only one agent in the office. What is the average waiting time for a customer?

A. 4.167 minutes

B. 6.75 minutes

C. 1.845 minutes

D. 2.214 minutes

9. John sells 300 packs of candies per week at $40 per pack. The candies are ordered from a supplier who charges John $60 per order and $20 per pack. John's annual holding cost percentage is 20%. Assume John operates 50 weeks a year. What is John's total ordering + holding cost per year if John orders 240 packs at a time?

A. $4,230

B. $5,190

C. $3,790

D. $2,700