When an object is located 40 cm to the left of a lens with a focal length f an image is produced at a distance of L away from the lens. The lens is replaced with another lens having a focal length of 3f the image is now located at a distance of 2L from the lens.

(a) What is the distance L? Hint: Write out an equation for each case and try combining them. 

(b) What is the focal length f?

(c) What type of images are being created (virtual or real)?