Answer Happy

A dollar store has six checkout lanes. The clerks in each lanehave the same​ abilities, with each clerk being able to checkout acustomer in 3 minutes on average. At its busiest​ times, customersto the dollar store arrive at the checkout counters at the rate of40 per hour.   
1. The average waiting time if all 6 checkout lanesare being used is?
2. The dollar store is contemplating closing one of the checkoutlanes. If they reduce the number of lanesfrom 6 to 5 then how will customer wait time beaffected during the busiest store​ hours?
3. The average waiting time when there are 5 checkoutlanes will increase by?
4. If the dollar store reduces the number of checkoutlanes from 6 to 5​, how will the averageprocessing time​ (service time)​ change?
λ/μ 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50 6.00 6.50 1 Number of servers (M) 2 3 4 5 6 0.3333 0.0455 0.0068 0.0010 0.0001 1.9286 0.2368 0.0448 0.0086 0.0016 0.0003 7 8 0.8889 0.1739 0.0398 0.0090 0.0019 0.0004 3.5112 0.5331 0.1304 0.0339 9 10 0.0086 0.0021 0.0005 1.5283 0.3542 0.0991 0.0282 0.0078 0.0020 0.0005 5.1650 0.8816 0.2485 0.0762 0.0232 0.0068 0.0019 2.2165 0.5695 0.1801 0.0590 0.0190 0.0059 6.8624 1.2650 0.3910 0.1336 0.0460 0.0155 2.9376 0.8104 0.2788 0.1006 0.0361 8.5902 1.6736 0.5527 0.2039 0.0767 3.6830 1.0709 0.3920 0.1519 10.3406 2.1019 0.7298 0.2855