On a certain exam, tony corrected 20 papers and found the mean for his group to be 60. alive corrected the remaining 10 papers and found that the mean for her group was 50. what is the mean of the combined group of 30 students?

Somone me i want to know what 18 hours out of 24 hours in a fraction

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

Solve this system of equations. 12x − 18y = 27 4x − 6y = 10