L&P Janitorial Service provides cleaning services to many clients, including the Johnson Tower complex. L&P personnel begin their operations at 10:00 P.M. and must leave before 6:00 A.M. the following...

L&P Janitorial Service provides cleaning services to many clients, including the Johnson Tower complex. L&P personnel begin their operations at 10:00 P.M. and must leave before 6:00 A.M. the following morning. Certain cleaning operations must be completed before others are started, as illustrated by the following network. The times are in minutes.

a. Prepare a chart giving the earliest and latest start and finish times and the slack times for each cleaning activity. Express the earliest and latest start and finish times as actual clock times (i.e., 10:00 P.M ., etc.).

 b. L&P Janitorial wants to conserve costs and will send the minimum number of workers required to complete a cleaning project. Employees work eight- hour shifts, and any worker can perform any of the cleaning operations. Show how the Johnson Tower complex project can be completed using only two workers. Give a schedule for each worker.