The PE coach is playing a game with the kinder kids She brings out a bag that has 3 red marbles, 2 blue and 4 yellow. What is the theoretical probability of pulling a red? Write it in simplest form

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