Final answer:
The subject of this question is Mathematics and it is at a High School level. The question is about the arrival and waiting times of customers at a barber shop.
Step-by-step explanation:
The subject of this question is Mathematics and it is at a High School level. The question is asking about the arrival and waiting times of customers at a barber shop. It provides information about the arrival rate and the average time it takes for a haircut. The question also asks for the probability of certain events occurring.