The probability that I have to wait at the traffic lights on my way to school is 0.45. Find the probability that on 3 consecutive mornings I have to wait:

Question

A) Once

B) Twice

Answer 1

A) prob(waiting once out of 3)
= C(3,1)(.45)(.55^2)

B) Prob(waiting twice of 3 days)
= C(3,2) (.45^2)(.55)
= ...