7!/10!
I need help please

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

Plz a. s. a. p. the table shows the number of male and female contestants who did not win a prize. what is the probability that a randomly selected contestant won a prize, given that the contestant was female? write the probability as a percent. round to the neares tenth, if needed.

In the polynomial below, what number should replace the question mark to produce a difference of squares? x2 + ? x - 36