Can someone help please Suppose that Santa will have his pic

Can someone help please!!

Suppose that Santa will have his picture taken with a child at a Poisson rate of 24 children per hour. You arrive with a child, and there are only 3 children ahead of you waiting to see Santa. What is the probability you will have to wait more than 8 minutes to meet santa? Can someone help please!!

Solution

you left something out of this question, which makes it difficult. The waiting time per child is exponential with mean (1/24), but I don\'t know how many children there are. The total waiting time should be gamma