A letting company is interested in modelling the number of times a police car passes along a particular street. The local station estimates on average a car passes down that street about 3 times each night.

(a) What distribution would be the best choice to model this? Give reasons for your answer.

(b) Find the probability that on a given night, no cars pass down that street

(c) What assumptions have you made in your answer to (b)? Are they likely to be true here? Give reasons for your answer.