Reasoning, Mental Ability and Aptitude
What this domain tests
Number and letter series, analogies, coding–decoding, blood relations, direction sense, ranking, linear and circular seating, syllogism, inequalities, clock and calendar, and non-verbal items such as mirror images, embedded figures and paper folding.
Working rules
- Learn A=1 to Z=26 and the reverse positions; most letter-series items collapse once this is automatic.
- In circular seating, fix one person, mark the facing direction, and remember that 'facing outside' reverses left and right.
- In syllogism, accept only what is definitely true in every possible arrangement.
- In direction sense, draw the path and compute the shortest distance with Pythagoras rather than tracing each step.
Worked example
If COURT is coded as DPVSU, how is JUDGE coded? Each letter moves one place forward: C→D, O→P, U→V, R→S, T→U. Applying the same shift: J→K, U→V, D→E, G→H, E→F, giving KVEHF.
Traps that cost marks
- Treating 'All A are B' as convertible: it does not imply 'All B are A', so 'All clerks are officers, some officers are examiners' does not yield 'some examiners are clerks'.
- 'Some A are B' does convert, and many candidates wrongly reject it.
- In either–or conclusions, check that the two conclusions are complementary and cannot both be true.
- Missing the difference between 'left of' and 'immediate left' in seating puzzles.
- In number series, testing only addition and subtraction when the pattern alternates between two operations.