Sapir buys 60 bags. She pays £3 for each bag. Sapir sells 1/2 of the bags for £5 each. She sells 1/3 of the bags for £4 each. Sapir wants to make a total profit of £75. How much should she sell each of the remaining bags for? (Must show working out).

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