Me ayudan y les doy corona y estrella​

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 f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

The vertices of a triangle are a(7.5), b(4,2), and c19. 2). what is