Reasoning and Mental Ability
Reasoning and Mental Ability tests speed on standard puzzle types rather than mathematical depth. Verbal items dominate - series, coding–decoding, blood relations, direction sense, ranking, syllogism and seating - with a few non-verbal figures.
Rules that solve most items
- Letter positions: E=5, J=10, O=15, T=20, Y=25 (EJOTY). Opposite letters sum to 27 (A–Z, B–Y, C–X).
- Series: check differences first, then squares or cubes, then alternating patterns, before assuming a prime-number rule.
- Blood relations: draw a family tree, mark gender symbols, and never assume gender from a relation word.
- Direction sense: sketch a compass; displacement uses Pythagoras on net north–south and east–west movement.
- Syllogism: draw minimal Venn diagrams. "Some A are B" converts to "some B are A", but "all A are B" does not convert.
Worked example
Pointing to a photograph, a man says, "She is the daughter of my grandfather's only son." How is she related to him? Reasoning: "my grandfather's only son" can only be the speaker's father, since the grandfather has exactly one son. That man's daughter is therefore the speaker's sister. The word "only" is the constraint that removes the cousin trap; without it, a cousin would also fit.
Traps
- Assuming a doctor or engineer is male in blood-relation puzzles.
- Treating mirror and water images alike: a mirror reverses left–right, water reverses top–bottom.
- Counting only the smallest triangles and missing composite figures.
- Ignoring the "no conclusion follows" option in syllogisms.
Speed rule
Work from the options and eliminate; a full derivation is rarely needed to score.