X6=729.help find out whats the x

You decide instead to take the train there. the train will take 135 minutes. convert this into hours and minutes.

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

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?