Question as shown below in the image:

Carlos spent 1 1/4 hours doing his math homework he spent 1/4 of his time practicing his multiplication facts how many hours to carlos been practicing his multiplication facts

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

Solve this problem! extra ! 3025/5.5 = a/90.75 / = fraction