Given,
$\mathit{u}=-15\mathrm{cm},\mathit{f}=20\mathrm{cm}$
$\frac{1}{\mathit{f}}=\frac{1}{\mathit{v}}-\frac{1}{\mathit{u}}$
$\frac{1}{20}=\frac{1}{\mathit{v}}+\frac{1}{15}$
$\frac{1}{\mathit{v}}=\frac{1}{20}-\frac{1}{15}$
$\mathit{v}=-60\mathrm{cm}.$
Four characteristics of the image formed by the lens are :
(i) Virtual, (ii) Erect, (iii) At a distance of 60 $\mathrm{cm}$ on the same side of the lens as the object, (iv) Enlarged or magnified image.