Two thin convex lenses \(A\) and \(B\) of focal lengths \(20\,\mathrm{cm}\) and \(30\,\mathrm{cm}\) respectively are placed coaxially in air with a separation between them. If an object is placed in front of lens \(A\) at a distance of \(45\,\mathrm{cm}\) from lens \(A\), the final image is formed at a distance of \(30\,\mathrm{cm}\) from lens \(B\). The distance between the two lenses is