Consider a restaurant located in the business section of a city. How many seats should it have available if it wishes to serve at least 95 % of all those who desire its services in a given hour, assuming that potential customers (each of whom takes at least an hour to eat) arrive in accord with the following schemes: (i) 1000 persons pass by the restaurant in a given hour, each of whom has probability 1/100 of desiring to eat in the restaurant (that is, each person passing by the restaurant enters the restaurant once in every 100 times); (ii) persons, each of whom has probability 1/100 of desiring to eat in the restaurant, pass by the restaurant at the rate of 1000 an hour; (iii) persons, desiring to be patrons of the restaurant, arrive at the restaurant at the rate of 10 an hour.