Urgent math !
which shows the conversion of 0.21 millimeters to inches?
there is 0.03937 inch in 1 millimeter.
a.
0.21 mm × 0.03937 in./mm = 0.0083 inches
b.
0.21 mm + 0.03937 in./mm = 0.24937 inches
c.
0.21 mm ÷ 0.03937 in./mm = 5.34 inches
d.
0.21 mm × 0.03937 in./mm = 8.3 × 10^-2 inches

Find the solution of system of equation y= x-4 y=4x+2

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

Twelve less than a number is at most 20