question_answer

The average time between two arrivals of customers at a counter in a ready-made store is 4 min. The average time of the counter clerk to serve the customer is 3 min. The arrivals are distributed as per Poisson distribution and the services art exponential distribution. The probability that a customer arriving at the counter to wait, is:

A) Zero                             

B) 0.25

C) 2 and 3            

D) 0.75