Starting at any time t, the number NÏ of hamburgers sold at a White Castle in the

Question:

Starting at any time t, the number NÏ„ of hamburgers sold at a White Castle in the Ï„ minute interval (t, t + Ï„) has the Poisson PMF

(a) Find the expected number E[N60] of hamburgers sold in one hour (60 minutes).
(b) What is the probability that no hamburgers are sold in the 10-minute interval starting at 12 noon?
(c) You arrive at the White Castle at 12 noon. You wait a random time W (minutes) until you see a hamburger sold. What is the PDF of W?