Question:-
The inter-arrival times at a tool crib are exponential with an average time of 10 minutes and the length of the service time is assumed to be exponential with mean 6 minutes. The probability that a person arriving at the booth will have to wait is equal to:
Option (A)
0.15
Option (B)
0.40
Option(C)
0.42
Option(D)
0.6
Correct Option:
(D)
Question Solution:
Probability that person has to wait
= r = (l/m)
l = (60/10) = 6 persons/hour
m = (60/6) = 10 persons/hour
Therefore probability that person has to wait
= (l/m) = (6/10) = 0.6
question-answer-faq-8920