How can we tell if 2 fractions added together make a sum greater than 1?

Yo y do yall have 2 stars that means yall wrong bro

1: 4 if the wew 35 surfboards at the beach how many were short boards?

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