The Lens Formula Relating the Image Distance, P , to the Focal

The lens formula relating the image distance, p , to the focal length, f , and object distance, s , is
The magnification of a lens is
A magnifying glass with focal length 15 cm is placed 10 cm above a stamp. The image of the stamp is located

A) 30 cm above the magnifying glass.
B) 30 cm below the magnifying glass.
C) 30 cm above the stamp.
D) 30 cm below the stamp.
E) 15 cm from the magnifying glass.