The number of boys and girls in a class is 5: 7. the number of girls is 8 more than the boys. find: i. number of boys in the class. ii. number of girls in the class. iii. total strength (total number of students) of the class.

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