What two numbers multiply to be 24, but add to equal -11

Which of the following three dimensional figures has a circle as it’s base

If the sales price of a dvd is $20 and the markup is 34%, what is the cost of the dvd?

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