By multiplying integers what is the total of (-10)(0)

Ling listed all of the factors of a mystery number: 1,2,4,8,16,32 what is the mystery number?

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

What is the area of the shaded sector?