3.3.16 At Newark airport, your jet joins a line as the tenth jet waiting for tak
ID: 3221166 • Letter: 3
Question
Explanation / Answer
a. L1 jets must land before a jet takes off. Each jet lands with a probability =2/3 each minute and independent of each other.
So, probability of l jets landing before first take off = PL1(l) = (2/3)^l
b. Here we want P(W=10).
So, we want all jets to take off in sequence and no jet to land during that time so that 10th jet can take off in 10 minutes
SO, probability is that no jet lands in 10 minutes = (1/3)^10
c. PMF of W : P(W=w) = 1/3^10 * (2/3)^(W-10), W>=10
This is because 10 jets take off and W-10 land during time W.