1. (Poisson Approximation). Assume that each of 2000 individuals living near a nuclear power plant is exposed to particles of a certain kind of radi- ation at the rate of one per week. Suppose that each hit by a particle is harmless with probability 1 - 10-5 and produces a tumor with probability 10-5. Find the approximate distribution of:
(a) the total number of tumors produced in the whole population over a one-year period by this kind of radiation;
(b) the total number of individuals acquiring at least one tumor over a year from this radiation.
2. * (Poisson Approximation). Twenty couples are seated at a rectan- gular table, husbands on one side and wives on the other, in a random order. Using a Poisson approximation, find the probability that:
(a) exactly two husbands are seated directly across from their wives;
(b) at least three are;
(c) at most three are.