An average of 5 cars arrive per hour at a restaurant

An average of 5 cars arrive per hour at a restaurant. Assume that the number of cars arriving per hour follows Poisson distribution. 

(i) What is the probability that exactly 5 cars will arrive in a given hour ? 

(ii) What is the probability that at least 3 cars arrive in a given hour ? 

(iii) What is the probability that at most 3 cars arrive in a given hour ?