What is the average customers in queue and average waiting time when only 9 check-in counters are working?

ABC Airlines wanted to reduce their operating
cost. They hired a consultancy service to look in to various
options. One of the options suggested is eliminate the manned
Check-in counters and introduce electronic check-in stations. ABC
Airlines wanted to do the trial in one airport to see the impact.
They used the Indianapolis Airport for their study. The observation
is as follows
Average 2 customers arrive per minute and it takes 4 minutes to
service a customer. They installed 10 Electronic Check-in counters.
They promised if the average waiting time exceeds 1 minutes they
will pay $ 10 gift voucher towards the next ticket purchase.
Answer the following questions
What is the average customers in the queue and average waiting
time when all 10 check-in counters are working?
What is the average customers in queue and average waiting time
when only 9 check-in counters are working?
The formulas are the ones provided for the course so Im limited
to that

arrival rate u service rate of a single server c number of identical service channels cu stable system n13 average number waiting in line n ti Queuing Models 1) nu 0.5 use “15 Qformula.xlsm” to compute M/M/c tl average time waiting in line