For an infinite-source, single server system with an arrival rate of 15 customers per hour (Poisson) and service time of 2 minutes per customer (exponential), what is the probability there will be fewer than 2 customers in the system?

Select one:

a. 0.50

b. 0.75 (Correct anwer, but how ?)

c. 0.875

d. 1.0

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A bank is designing a new branch office and needs to determine how much driveway space to allow for cars waiting for drive up teller service. The drive up service will have three tellers and a single waiting line. At another branch of the bank in a similar setting, the average service time for drive up tellers is 4 minutes per customer and average arrival rate is 36 customers per hour. It is expected that the new bank will have similar characteristics. How many spaces (in the line) should be provided to have a 96% probability of accommodating all of the waiting cars in the line?

Select one:

a. 12

b. 14

c. 10

d. 13

e. 11

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