In the queuing theory, the relationship between the expected number of customers in the system (or queue) and expected waiting timing the system (or queue) is known as

In the queuing theory, the relationship between the expected number of

1.	In the queuing theory, the relationship between the expected number of customers in the system (or queue) and expected waiting timing the system (or queue) is known as
A.	Kendall’s formula
B.	Little’s formula
C.	Bellman’s formula
D.	Erlang formula
Answer» C. Bellman’s formula