1. The problem statement, all variables and given/known data An object is placed at a distance p = 25 cm from a concave mirror of focal length f = 10 cm. About the mirror is poured a small amount of liquid whose refractive index n = 1.4. Determine the distance of the image formed by this optical system to the mirror. 2. Relevant equations i think: f = p.p'/p + p' d'/d = nobserv./nobject 3. The attempt at a solution Hello, I tried to solve this problem, but I'm confused about the answer. I found 14 cm, but I think that my solution isn't right. So .. could anyone explain me how to solve this problem and the final answer ? Thanks.