The focal length of a concave mirror is 50cm. Where an object be placed so that its image is two times and inverted

The focal length of a concave lens is 30 cm. Where should an object be placed so that its image is 1//10 of its size ?

The focal length of a concave mirror is 20 cm . Where should an object be placed to get an image magnified twice?

Answer the following questions: The focal length of a concave mirror is 15cm. Where should on object be placed in front of this mirror so as to obtain an image which is real, inverted and of the same size as the object? Justify your answer.

The focal length of a concave mirror is 12 cm . Where should an object of length 4 cm be placed so that a real image of 1 cm length is formed ?

At what distance in front of a concave mirror of focal length 10 cm, an object be placed so that its real image of size five times that of the object is obtained?

At what distance in front of a concave mirrorof focal length 10 cm, an object be placed so that its virtual image of size five times that of the object is obtained?

The focal length of a concave lens is 20 cm, if an object is placed at a distance of 50 cm in front of this concave lens, where is the image formed ? What is the nature of the image ?