Lean Burger's drive through receives 20 customers in every ten minutes of business time between 12:00 - 1:00 PM. In ten minutes of operation during this time of day:
a. What is the probability that no customer arrives?
b. What is the probability that only 1 customer arrives?
c. What is the probability that 2 customers arrive?
d. What is the probability that 3 customers arrive?
e. What is the probability that less that four customers arrive?