Anyone help me please

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Abe is a triangle. can you use the sss postulate or the sas postulate to prove triangle abc = triangle aed? by sss only neither apply both apply by sas only

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