Find the limit limx→+[infinity]ex+e−xex−e−x limx→+[infinity]ex+e−xex−e−x Enter inf for [infinity] [infinity] , -inf for −[infinity] −[infinity] , and DNE if the limit does not exist. HINT: Factor ex ex out of the numerator and denominator

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