Cars coming along Magnolia Street come to the fork in road and have to select either Willow Street or Main Street to continue. Suppose that number of cars which arrive at fork in unit time has Poisson distribution with parameter = 4. Car arriving at fork chooses Main Street with probability 3/4 and Willow Street with probability 1/4. Let X be random variable which counts number of cars that, in given unit of time, pass by Joe's Barber Shop on Main Street. Determine the distribution of X?