which formulas and steps can help me solve problems like these? thank you!

MCQ1. An object is placed upright on the axis of a thin converging lens with a focal length jut a distance of three focal lengths (3/) from the center of the lens. What is the ratio of the height of the image to the height of the object? MCQ2. Light passes from a medium of index of refraction n, into a second medium of index of refraction ms. The critical angle for total internal reflection is Out In order for total internal reflection to occur, what must be true about zo. ms, and the incident angle ? A) ha > my and On Den By na > 16 and 0. Gerit Dy no