Physics - Geometrical Optics Question with Solution | TestHub

Two thin lenses have a combined power of$+9 \mathrm{D}$. When they are separated by a distance of$20 \mathrm{cm}$, their equivalent power becomes$+\frac{27}{5}\mathrm{ }\mathrm{D}.$Their individual powers (in$\mathrm{dioptre}$) are