The Demand for Ballard's Glass Company's Products Varies, Ranging from 10

Multiple Choice

The demand for Ballard's Glass Company's products varies, ranging from 10 to 20 windows a day with an average of 15. John Ballard works eight hours a day, five days a week. Each order is one window, and each window takes 26 minutes to install. The company plans to add doors to its product line and anticipates selling an average of 5 doors per day. Each door takes 12 minutes to install. What is the average waiting time if Ballard is the only worker?

A) 38.0 minutes
B) 112.4 minutes
C) 181.0 minutes
D) 410.0 minutes
E) 523.4 minutes