This document discusses problem solving and different types of problems. It defines a problem as a purposeful activity aimed at removing difficulties through reasoning. Problems are classified as mental, symbolic, or real. Mental problems involve contemplation, while symbolic problems require diagrams or models. Real problems are physical. The document also outlines functions and values of problem solving, including giving training in reasoning, developing proper thought habits, and improving attitudes. It provides characteristics of good problems and lists the typical steps in problem solving: recognizing the problem, proposing hypotheses, evaluating solutions, and verifying the accepted solution.