4. (2 points) Alice goes to the bank to make a withdrawal, and is equally likely to find 0 or 1customer ahead of her. The service time of the customer ahead, if present, is exponentiallydistributed with parameterλ. What is the CDF of Alice’s waiting time?5. (3 points) Vehicles approaching a certain road junction from town A can either turn left,turn right or go straight on. Over time it has been noted that of the vehicles approachingthis particular junction from town A, 55% turn left, 15% turn right and 30% go straighton. The direction a vehicle takes at the junction is independent of the direction any othervehicle takes at the junction.a. Find the probability that, of the next three vehicles approaching the junction fromtown A, one goes straight on and the other two either both turn left or both turnright.b. Three vehicles approach the junction from town A. Given that all three drivers choosethe same direction at the junction, find the probability that they all go straight on.6. (3 points) The volume of soup in Super Soup cartons has a normal distribution with meanμmillilitres and standard deviation 9 millilitres.