In the telephone exchange of a certain university, calls come in at a rate of 5 every 2 minutes. Assuming a Poisson distribution, the average number of calls per second is: a) 1/8 b) 1/12 c) 1/10 d) 2/5 e) 1/24

To find the average number of calls per second, we need to convert the rate from calls per 2 minutes to calls per second.

Step 1: Convert the rate to calls per minute:
The rate is given as 5 calls every 2 minutes. So, the rate is 5/2 calls per minute.

Step 2: Convert the rate to calls per second:
Since there are 60 seconds in a minute, the rate is (5/2) / 60 calls per second.

Step 3: Simplify the expression:
(5/2) / 60 = 5 / (2 * 60) = 5 / 120 = 1/24

Answer: The average number of calls per second is 1/24. Therefore, the correct option is e) 1/24.