In 2015, Tamya spent 100 hours reading. In 2016, she has only read 9.5 hours. How many more hours does she have to read in order to also read 100 hours in 2016?​

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