A Thin Double Convex Lens Is to Focus the Image

Short Answer

A thin double convex lens is to focus the image of an object onto a screen so that the image is life-sized.The lens surfaces have equal radii of curvature of 112 cm,and the refractive index of the lens material is 1.500.
(a)How far from the lens should the screen be placed?
(b)How far is the screen from the object?