Reasoning and Mental Ability
What this domain tests
Series (number, letter, figure), analogy, coding-decoding, blood relations, direction sense, order and ranking, syllogism, seating arrangement, and non-verbal items such as mirror images, water images and paper folding. The examiner rewards systematic elimination over guessing.
Core rules
- Number series: check differences first, then ratios, then two interleaved alternate-position sequences.
- Coding: test letter-shift patterns (±n), reversal, and position-value sums (A=1 … Z=26).
- Direction sense: draw axes. Facing north, a right turn means east; two opposite turns return you to the original facing.
- Blood relations: draw a family tree and mark gender only after the wording confirms it.
- Syllogism: "some A are B" is reversible; "all A are B" is not reversible, and nothing outside the statements may be assumed.
Worked example
Find the next term: 2, 6, 12, 20, 30, ? Differences are 4, 6, 8, 10 - rising by 2 each time, so the next difference is 12 and the term is 30 + 12 = 42. Shortcut check: the terms follow n(n+1) for n = 1, 2, 3, 4, 5, so the next is 6 × 7 = 42. Both routes agree.
Traps that cost marks
- Guessing gender from a name in blood-relation puzzles (the word "cousin" gives none).
- Reporting the direction finally faced instead of the direction of the final position from the start.
- In seating puzzles, applying left and right from your own side when people face the centre.
- Treating a mirror-image question as a water-image question, which flips the wrong axis.