If there is a circuit that is being used 0.75 Erlang then how much of that circuit is being used in CSS?

A. 36

B. 25

C. 2.7

D. 27

E. 0.625

Answer: D.) 27

Explanation:

In Traffic Engineering, instead of a unit like Erlang, it is customary to use a smaller unit, the CCS (centum call-seconds), which defines a traffic cursed by a call that lasts 100 seconds.

As we have 3600 seconds in an hour, if we would have all the hour busy with calls of 100 seconds, we would have exactly 36 calls in order to add to 1 Erl of traffic.

So we can define this equivalence: 1 Erl = 36 CCS.

Conversely, 1 CCS = 1/36 Erl.

So, if we want to compute how many CCS are equivalent to 0.75 Erl, we can use a simple direct proportion calculation, as follows:

1/36 Erl ⇒ 1 CCS

∴ 0.75 Erl = 0.75/1/36 = 27 CCS