Old tests and problems (and solutions when available) are provided in this section. Although most of the questions are self explanatory, in some cases, it is necessary to hear and understand the corresponding lecture for the "whole story." For example, there might be certain assumptions or approximations provided in the lectures that are not specifically stated in the test and homework problems. Also, in many problems, the parameters listed are not realistic but are merely assigned convenient values to speed along the grading process. If solutions are not given here, they are not available. Since there is sometimes overlap in topics between courses, the use of the "search" feature will help locate topics of interest. Unfortunately, some of the scanned solutions are difficult to see--I might be able to improve this quality at a much later date.