I ain't ever seen two pretty best friends

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

If private savings 'v' = 0.75s and total savings 's' equals $4.20 billion, solve for public and private savings.

Solve each quadratic equation by factoring and using the zero product property. n^2 - 49 = 0