Question

The probability of a customer arrival at a grocery service counter in any one-second period is equal to 0.1. Assume that customers arrive in a random stream and hence that an arrival in any one second is independent of all others. Let Y be the number of one-second periods until the first customer arrives. a) Find the probability function for p(y). b) Find the probability that the first arrival will occur during the third one-second interval (Y=3). c) Find the probability that the first arrival will not occur in the first two one-second intervals.