Solve the all parts of given question:
Question: A light bulb is 3.2m from a wall.
Part A: What is the focal length of a lens that will form an image on the wall that is twice the size of the light bulb?
Part B: What is the position *measured from the bulb) of the lens?
I don't just need an answer, work and explanations/walkthrough would be much appreciated! Thanks.