1. The problem statement, all variables and given/known data Given only the distance between the object and its image (p +q), how is it possible to find p, the distance of the object from the convex lens? 2. Relevant equations 1/p + 1/q = 1/f in this case, p + q =40 also, the image is smaller than the original, so p > 2f 3. The attempt at a solution I don't understand how to find p if q and f are unknown. I tried solving for q as q=40-p, but that didn't take me anywhere.