Question

Find the position (in $cm$ and only magnitude) of the final image of the object for the arrangement shown.

Answer 1

Answer: 24

For convex lens:
$\frac{1}{v}-\frac{1}{(-20)}=\frac{1}{40}$
$\Rightarrow v=-40cm$
This image acts as object for concave lens.
For concave lens:
$\frac{1}{v}-\frac{1}{(-60)}=\frac{1}{-40}$
$\Rightarrow v=-24cm$