Reasoning Ability: Syllogisms, Puzzles and Inequality
What is tested
Reasoning Ability covers syllogism, puzzles and seating arrangement (linear, circular, floor, box), inequality, coding–decoding, blood relations, direction sense, order and ranking, alphanumeric series, and data sufficiency. Puzzles carry the most marks and the most time; syllogism and inequality are the fastest scoring clusters.
Rules that decide answers
- Conversion: All A are B → Some B are A. Some A are B → Some B are A. No A is B → No B is A.
- Possibility: a conclusion is true in the possibility case unless it is contradicted by every valid diagram. "All A are B" does not rule out "Some A are not B" unless the statement forbids it.
- Either–or: arises when two conclusions share the same subject and predicate with complementary forms (Some A are B / No A is B), and neither follows alone but one of them must be true.
- Inequality: combine only same-direction signs. A > B ≥ C gives A > C. Never combine > with < to produce a definite relation.
- Blood relations: draw a tree, and fix gender only where the question states it or a term (father, sister) requires it.
Worked example
Statements: All pens are books. Some books are red. Conclusions: I. Some pens are red. II. Some books are pens. From "All pens are books", valid conversion gives "Some books are pens", so II follows. The red books may be entirely outside the pen set, so I does not follow. Answer: only II follows.
Traps that cost marks
Do not import real-world knowledge into puzzles, and do not assume a person's gender from a name. In circular seating, confirm whether people face the centre or outward before fixing left and right. In direction sense, track net displacement separately on the north–south and east–west axes. Finally, do not chase a puzzle you cannot crack in two minutes - the marks per minute are poor.