PLEASE! BRAINLIEST!
How did the Silk Road help China overcome its geographic isolation?
It provided better trade routes north of China.
It helped connect China to countries to the west.
It encouraged contact with countries to the south.
It led to increased communication with lands to the east.

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