A concave reflector of radius of curvature 110 cm is used by a reflecting type telescope. What will be the focal length of eyepiece required to obtain a magnification of 20?

Explanation

To solve the problem, we need to find the focal length of the eyepiece required to achieve a magnification of 20 for a reflecting telescope that uses a concave mirror with a radius of curvature of 110 cm.

### Step-by-Step Solution:

1. **Identify the Radius of Curvature (R)**:
The radius of curvature of the concave mirror is given as:
\[
R = 110 \, \text{cm}
...