2. At a checkpoint for drink driving, suppose that on an average of 3 cars per minute arrive (interarrival times follow exponential distribution). A checkpoint can check an average of 4 cars per minute (the time to check a car is exponentially distributed) for drink driving. We assume that there is only one checkpoint, answer the following questions: (a) What is the probability that a car will have to wait before being checked for drink driving? (b) On average, how many cars are waiting in line to enter the check- point? (c) On average, how long will a car spend at the checkpoint