Arrival times of poisson process

The arrival times of customers in a bakery can be modeled by a Poisson process (NtltBO with some rate A > 0. On average, there are four arrivals per unit of time. (i) Find the value of A. (ii) Compute the probability of the following event: {the second customer arrives before time 2, two customers arrive during [4, 10], and at least one arrives in [8, 16]}. (iii) For t 2 0, compute the covariance Cov(Nt, Nt+4). (iv) We now assume that upon entering the bakery, each customer decides to buy either one bread with probability %, or one croissant with probability % (i.e. the customer chooses exactly one of these two options, it never chooses both), independently of the other customers. What is the distribution of the correSponding counting processes, denoted (respectively) by (N59),20 and (N320