An object 1 cm high is held near a concave mirror of magnification 10. How tall will be the image?

Calculate the distance of an object of height h from a concave mirror of focal length 10 cm so as to obtain a real image of magnification 2 .

A concave mirror forms an image of an object, magnified 4 times. When the object is moved through 5 cm along the axis of the mirror, the magnification of the image is 5. What is the focal length of the mirror?