Need help in this can someone help

If x = 12 and y = 3, what is the value of x - y 2? 81 6 3 18

Diana is painting statues she has 7/8 of a liter of paint each statue requires 1/20 of a liter of paint how many statues can she paint?

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters