Logical and Abstract Reasoning
Core concepts
Logical reasoning includes syllogisms, seating and ranking, blood relations, coding-decoding, series, analogies, assumptions, strengthening and weakening arguments, and deductive validity. Abstract reasoning includes pattern series, figure rotation, mirror images, paper folding, embedded figures, and matrix completion. The goal is to find the rule that governs the data, not to rely on familiarity or guesswork.
Traps
A frequent trap is the converse error: from All A are B, one cannot infer All B are A. Some statements are compatible with several arrangements, so a definite conclusion is unwarranted. In seating puzzles, ignore extra information only after confirming it is irrelevant. In figure series, check multiple features: number of sides, rotation, shading, symmetry, and position. Avoid overcomplicating a simple rule.
Worked example
All firefighters are trained. Some trained people are swimmers. What follows? No definite conclusion links firefighters and swimmers. The swimmers who are trained may or may not include firefighters. Options saying some firefighters are swimmers, or no firefighter is a swimmer, both go beyond the premises. Only restatements of the given statements are valid.
Rule of thumb
Draw a Venn diagram or table, test each conclusion against a possible counterexample, and reject any option that is merely plausible. For abstract series, name the changing features in order before selecting the next figure.