problem two is a poisson distribution. The only trick here is to convert the rate of 1/6 car per minute to the # of cars per hour. Once you have the proper distribution just evaluate it's CDF at 5.

in problem 1 we assume that the whole days work is lost 33% of the time when it rains? So we are basically trying to determine the number of days out of 85 that the humidity messes up and everything is ruined.

This is a binomial distribution. with N=85, and p=33%=0.33 you can look up the distribution and derive the mean and variance easily enough. You're going to get numbers that are in units of #days of failure.