Which numerical pattern is a nonlinear progression 0.5,1,2,4,...

A.0.5 , 1 , 2 , 4 , ...
B.−13,−10,−7,−4,.
C.15,11,7,3,...
D.−29,−19,−9,1,...

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