For an M/G/1 queue, = 12 per hour, = 24 per hour, and the standard

For an M/G/1 queue, λ = 12 per hour, μ = 24 per hour, and the standard deviation of the service time σ = .05 hour.  Which of the following statement is incorrect? 

a. The average number of customers in the system = 1.11

b. The average time a customer spends in the system = 0.0925 hours

c. The probability that a customer does not have to wait = 0.5

d. The probability that there are exactly two customers in the system = 0.050

e. None of the above