A candle 20 cm high is placed 40 cm in front of the center of a thin lens. This lens has a focal length of 10 cm. A second thin lens, also with a focal length of 10 cm, is placed 40 cm from the first. Find:
a) The location 
of the image due to the first lens and its
magnification. Indicate whether the image is real or virtual.
b) The location 
of the image (of the image of the first lens) of
the second lens. Find the overall magnification, and indicate
if the final image is real or virtual.
c) Draw a ray diagram to locate the image in agreement with your
answers to a and b. Be sure to include and label 3 rays that uniquely
specify the image locations.