AIEEE 2006 (Offline)Question 1
At a telephone enquiry system the number of phone calls regarding relevant enquiry follow Poisson distribution with an average of $5$ phone calls during $10$ minute time intervals. The probability that there is at the most one phone call during a $10$-minute time period is :
Probability
Solution
$P(X\le1)=e^{-5}(1+5)=\frac{6}{e^5}$.