Ray Optics

A thin plano-convex lens of focal length \(f\) is split into two halves one of the halves is shifted along the optical axis. The separation between object and image formed by one of the half-lenses is 2.4 and the magnification of same lens is 2. If \(f\) and \(d\) be the focal length of the lens and separation between the two halves respectively then