If focal length is 20 cm then what is radius of curvature of mirror ?

If focal length is 20 cm then what is the radius of curvature of the mirror?

Assume that an object is kept at a distance of 20 cm in front of a concave mirror. If its focal length is 30 cm then What is the magnification of mirror in this case ?

There is an object infront of convex mirror at a distance of 5 cm. If its focal length is 10 cm then What is its magnification ?

The ratio of the focal length of spherical mirror to its radius of curvature is

There is an object infront of convex mirror at a distance of 5 cm. If its focal length is 10 cm then What is the image distance ?