A lens is located 30 centimeter to the right of an object, with an image clearly focused on a screen 45 centimeter from the lens. When a second lens is placed 30 centimeter to the right of the first lens, the final image is shifted 15 centimeter to the right (so that it is now 60.0 cm from the first lens).
A) Evaluate the focal length of each lens.
B) Construct a ray trace to verify your calculations.