Bank tellers I am the only bank teller on duty at my local bank. I need to run out for 10 minutes, but I don’t want to miss any customers. Suppose the arrival of customers can be modeled by a Poisson distribution with mean 2 customers per hour.

a) What’s the probability that no one will arrive in the next 10 minutes?

b) What’s the probability that 2 or more people arrive in the next 10 minutes?

c) You’ve just served 2 customers who came in one after the other. Is this a better time to run out?