A railroad crew can lay 6 miles of track each day. They need to lay 168 miles of track. The length, L (in miles), that is left to lay after d is given by the following function. L(d)=168-6d How many days will it take the crew to lay all the track? How many miles of track does the crew have left to lay after 17 days?

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