A survey of downtown Chicago found that the typical city block had an average of five rats per block. This was true irrespective of whether or not there was construction occurring on that block. If this average is applicable across all city blocks, what is the probability that, in a sample of two city blocks taken together, there will be a total of five or fewer rats for those two blocks?
In my view, it is a Poisson distribution. Here the average is given, i.e., $\lambda=5$. (I have looked at the table even.) But I'm not sure how to solve for two city blocks when taken together.