***Show Work (preferably in excel)***

Suppose that we the number of arrivals at the drive-up teller window of a bank on weekday mornings follows the Poisson distribution with an average arrival of 6 in a 15-minute period.

1. What is the probability that in one hour there will be no more than 29 arrivals at the drive-up teller window? Answer 0.8679
2. What is the probability that in a 10 minute interval there will be atleast 9arrivals at the drive-up teller window? Answer 0.0214
3. What is the probability that in a 30 minute interval there will be between 11 and 19 arrivals at the drive-up teller window? Answer 0.6315

I have provided the correct answers. I can figure out part A. I cannot figure out part B and C.