A bi- convex lens of focal length 15cm is infront of a planer  mirror. The distance between the lens and the mirror 10cm. A small object is kept at a distance of 30cm from the lens . The final image is

Object is placed at distance 2f from the lens so image ${\mathrm{I}}_1$ will be formed at a distance 2f on other side. The image ${\mathrm{I}}_1$ will behave like a virtual object for mirror. The second ${\mathrm{I}}_2$ image  will be formed at a distance 20cm in front of the mirror or at distance 10cm to the left hand side of the lens.
$\begin{array}{l}\frac{1}{\mathrm{v}}-\frac{1}{\mathrm{u}}=\frac{1}{\mathrm{f}}\\ \frac{1}{\mathrm{v}}-\frac{1}{10}=\frac{1}{15}\end{array}$
After calculate , v = 6cm
The final image at distance 16cm from the mirror. But this image be real . This is because ray of light is travelling from right to left.