The focal length

Given

Focal length of Concave mirror = -30cm (focal length of concave mirror is negative)

Distance of object from mirror = -20 cm (since object is on the left-hand side of lens and acc. To our sign convention)

Distance of image from mirror = ?

Formula Used

Mirror formula

Magnification formula

Using Mirror formula

V = 60 cm

Hence the image is at a distance of 60cm from mirror and is virtual.

Using magnification formula

M = 3

Hence, the image is 3 times the object and is erect.