What happens as n approaches infinity? Well, this term, right, lambda's a constant. As this approaches infinity, this term's going to approach 0, so you have 1 to the minus k. 1 to any power is 1, so that term becomes 1. So we have another 1 there. So there you have it. We're done. The probability that our random variable, the number of cars that pass in an hour, is equal to a particular number, you know, it's equal to 7 cars pass in an hour, is equal to the limit as n approaches infinity of n choose k times, well, we said it was lambda over n to the k successes, times 1 minus lambda over n to the n minus k failures.