Reasoning, Mental Ability and Logical Thinking
Reasoning tests pattern recognition, coded relationships, spatial arrangement, and valid inference. The section is usually non-technical but demands careful reading: one wrong assumption about direction, family relation, or quantifier can reverse the answer.
Core rules
- In series, check differences, ratios, squares, cubes, and alternating patterns before assuming a single rule.
- In coding-decoding, identify whether letters shift by position, reverse order, or use a keyword.
- In blood relations, draw a family tree and mark gender and generation explicitly.
- In direction sense, fix a reference point and track left/right turns relative to the facing direction.
- In syllogisms, accept only what necessarily follows; a possible conclusion is not a valid conclusion.
Worked example
A man says, 'She is the daughter of my grandfather's only son.' The grandfather's only son is the man's father. The daughter of the man's father is the man's sister. The answer is sister. The reasoning depends on reading 'only son' as identifying one person, not on the number of grandchildren.
Seating and puzzles
For linear arrangements, mark fixed positions first. For circular arrangements, note whether people face the centre or outside, because left and right reverse. For ranking puzzles, convert 'A is third to the left of B' into a position equation rather than a mental picture alone.
Traps that cost marks
Assuming a possible syllogistic conclusion is certain; forgetting that 'some A are B' does not imply 'some B are not A'; ignoring the facing direction in circular seating; confusing paternal and maternal relations; missing alternating series rules.
Key points
- Draw family trees and direction diagrams.
- In syllogisms, test necessity, not plausibility.
- Circular seating left/right depends on facing direction.
- Check alternating and combined series patterns.