Question

A quarterback for the Seattle Seahawks completes 54% of his passes. Let the random variable X be the number of passes completed in 20 attempts.

a) What is the probability that the quarterback throws three passes before he gets his first completion (on his fourth attempt)?
b) How many passes should the quarterback expect to make before he gets his first completion?
c) What is the probability that he has to throw more than 5 passes to get his first completion?