The probability of success in each trial is constant. We have a 12% success for each new person who comes through the line. The reason why this is not a binomial random variable is that we do not have a finite number of trials. Here, we're going to keep performing trials. We're going to keep serving people in the line until we get an SUV. What we have over here, when they say find the probability that Amelia registers more than four vehicles before she registers an SUV, this is the probability that V is greater than four. I encourage you, like always, pause this video and see if you can work through it.