Logical / Abstract Reasoning
What the section tests
Logical and Abstract Reasoning checks how quickly you detect patterns, follow rules, and visualize shapes. Expect number and letter series, analogies, coding–decoding, blood relations, direction sense, seating/ranking, syllogisms, Venn diagrams, figure series, mirror and water images, paper folding and cutting, embedded figures, and dice/cube problems.
Core rules to keep ready
- Series: check differences, then ratios, then alternating patterns; look for squares, cubes, primes and their ±1 variants.
- Letter positions: A=1 … Z=26. Reverse position = 27 − forward position; EJOTY (5,10,15,20,25) gives quick anchors.
- Coding–decoding: write the alphabet line and mark shifts; check both forward and backward shifts and reversal.
- Blood relations: draw a family tree; use + for male, − for female, horizontal for spouse, vertical for parent–child.
- Syllogism: draw minimal Venn diagrams. "All A are B" does not imply "All B are A"; "some" allows overlap only.
- Directions: track net displacement; use Pythagoras for shortest distance.
Worked example
Find the next term: 3, 7, 16, 35, 74, ? Check differences: 4, 9, 19, 39 - not constant. Try ×2 plus an increasing addend: 3×2+1=7; 7×2+2=16; 16×2+3=35; 35×2+4=74. The addend rises by 1 each step, so next is 74×2+5 = 153. Confirming with a second rule: each term is previous×2 + step number.
Traps that cost marks
- Locking onto the first pattern and not testing a second.
- In syllogism, converting "some A are B" into "some B are A" is valid, but "all A are B" into "all B are A" is not.
- Confusing mirror image (left–right) with water image (top–bottom).
- In seating, assuming all face north; read the facing direction first.
- In figure counting, missing overlapping regions.