Logical Reasoning and Mental Ability
The reasoning paper checks non-verbal and verbal logic: series (number, letter, figure), analogy and classification, coding-decoding, blood relations, direction sense, syllogism, seating and ranking, calendar and clock problems, and mirror or water images.
Core approaches
- Number series: check differences first, then ratios, then squares/cubes, then alternating patterns.
- Coding-decoding: write the alphabet with positions 1–26 and check the shift (+1, −2, reverse alphabet).
- Blood relations: draw a family tree and mark gender with symbols; 'brother of my father' is uncle.
- Direction sense: sketch the path, then apply Pythagoras for shortest distance.
- Syllogism: draw minimal Venn diagrams representing only what the statements definitely say.
Worked example
Find the next term: 3, 7, 15, 31, ? Reasoning: differences are 4, 8, 16 - doubling each time, so the next difference is 32 and the answer is 63. Check with the alternative rule: each term = previous × 2 + 1 (3×2+1 = 7, 7×2+1 = 15, 31×2+1 = 63). Both rules agree, which confirms the answer.
Traps that cost marks
Assuming a rule from only one or two terms; forgetting that a person's left and right reverse when they face south; treating 'some A are B' as reversible (it is, but 'all A are B' is not automatically 'all B are A'); and ignoring that blood-relation questions may hide a female name behind a neutral word like 'child'.