How far should an object be placed from the pole of a converging mirror of radius of curvature 40 cm to form a real image of the size exactly 4th the size of the object?

A concave mirror produces three times enlarged virtual image of an object placed at 10 cm in front of it. Calculate the focal length of the mirror.

A bright object 100 mm high stands on the axis of a concave mirror of focal length 100 mm and at a distance of 300 mm from the concave mirror. How big will the image be ?

When an object is placed at a distance of 50 cm from a concave spherical mirror, the magnification produced is, - Where should the object be placed to get a magnification of, -1/8?

An object is placed (a) 20 cm, (b) 4 cm, in front of a concave mirror of focal length 12 cm. Find the nature and position of the image formed in each case.