if shan has rupees 4800 left after spending 40% of his salary how much did he have in the beginning

In the diagram, the ratio of ab to ae is (1/2) . what is the ratio of the length of to the length of ?

Which system of linear inequalities is represented by the graph?

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