Write an e-mail (50-60 words) to one of your friends to ask him/her for some advice on improving your English speaking skill. Write your answer on the answer sheet. (0.4pt)You can use some suggested clues to develop your ideas.-Why you need his/her help-What difficulties you have with learning English-What expectations you hope to get from your friend.

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