Lynn asks Kieran to help her Factor the expression -4x y - 12x Z + 20x W how can kieron use this example to Help lin understand factoring

Four airplanes carrying a total of 400 passengersarrive at the detroit airport. the airplanes carry, respectively,50, 80, 110, and 160 passengers.a) one of the 400 passengers is selected uniformly at random.let x denote the number of passengers that were on theairplane carrying the randomly selected passenger. find var(x)for x as given in the problemb) one of the 4 airplane drivers is also selected uniformly atrandom. let y denote the number of passengers on the chosen driver’s airplane. find var(y) for y as given in the problem

Can someone me out here number 4 plz

Jim had 15 minutes to do 5 laps around his school what would his time be