Reasoning and Logical Analysis
Reasoning and Logical Analysis checks whether you can find a rule and apply it without assuming extra facts. The usual question types are number series, coding-decoding, blood relations, direction sense, syllogism, analogy and non-verbal figures.
Core rules and methods
- Series: test differences, ratios, squares, cubes and alternating patterns. Write the differences under the terms.
- Coding: convert letters to positions A=1 to Z=26. Check forward, backward and opposite-letter codes.
- Blood relations: draw a family tree. Use + for male and - for female, and connect only what the sentence states.
- Direction: draw north at the top. A left turn changes the facing direction, not the page direction.
- Syllogism: accept only conclusions that are true in every possible diagram. Some statements do not prove a universal conclusion.
Worked example
Find the next term: 2, 6, 12, 20, 30, ? Reasoning: differences are 4, 6, 8, 10. The next difference is 12. So 30 + 12 = 42. The pattern is also n(n+1): 1x2, 2x3, 3x4, 4x5, 5x6, so the next is 6x7 = 42. Answer: 42.
Traps that cost marks
- Stopping at the first pattern that fits two terms.
- Reversing left and right after a turn.
- In blood relations, assuming marriage or gender that is not stated.
- In syllogism, converting some A are B into all B are A.
Show your rough work in the margin. A drawn diagram is faster and safer than mental rotation.