Reasoning Ability
What the section tests
Reasoning Ability checks pattern recognition, logical deduction and spatial sense. Common question types are number and letter series, analogies, coding–decoding, blood relations, direction sense, syllogism, seating arrangement, ranking, odd-one-out and mirror or water images.
Core approaches
- Series: find the rule between consecutive terms; check differences, multiples, squares or alternating patterns.
- Coding–decoding: write the alphabet with positions 1–26 and note shifts, reversals or letter-pair rules.
- Blood relations: draw a family tree; use + for male and − for female, and horizontal lines for siblings or spouses.
- Direction sense: sketch each move and mark left or right turns relative to the current facing direction.
- Syllogism: draw minimal overlapping circles; do not assume a relation unless the statements force it.
Worked example
Find the next term: 3, 6, 11, 18, 27, ?
Reasoning: the differences are 3, 5, 7 and 9, which increase by 2 each time. The next difference is 11, so the next term is 27 + 11 = 38. Alternatively, the pattern is n² + 2 for n = 1, 2, 3, 4, 5, giving 1 + 2 = 3, 4 + 2 = 6, 9 + 2 = 11, and so on; for n = 6, 36 + 2 = 38.
Traps that cost marks
- In syllogism, treating “only a few” or “some” as “all”.
- Forgetting that a left turn changes the facing direction before the next move.
- Reversing the order of letters in coding questions.
- Ignoring a second possible pattern in a series; test the rule on all given terms.