Reasoning and Mental Ability: Series, Coding, Relations, Syllogism, Non-verbal
Reasoning and Mental Ability tests pattern recognition rather than syllabus knowledge: number and letter series, coding–decoding, blood relations, direction sense, ranking, syllogism, seating arrangement, clocks and calendars, and non-verbal figures.
Core rules
- Alphabet positions: A = 1 … Z = 26. Remember EJOTY (E = 5, J = 10, O = 15, T = 20, Y = 25); opposite letters sum to 27 (A–Z, B–Y, C–X).
- Clock: minute hand moves 6° per minute, hour hand 0.5° per minute; the hands coincide 11 times in 12 hours.
- Calendar: 100 years give 5 odd days, 200 give 3, 300 give 1, 400 give 0.
- Blood relations: draw a family tree with clear male/female symbols and never assume gender from a name or relation word.
Worked example 1 - number series
3, 7, 15, 31, ? Rule check: each term is previous × 2 + 1, so 3×2+1 = 7, 7×2+1 = 15, 15×2+1 = 31, and 31×2+1 = 63. Cross-check with differences: 4, 8, 16, next 32, and 31 + 32 = 63. Both routes agree, so the answer is 63.
Worked example 2 - coding
If MOBILE is written as NPCJMF (each letter shifted one place forward), then PHONE becomes QIPOF by the same shift.
Traps
- In direction sense, mixing up a left turn and a right turn after facing south.
- In syllogism, 'All A are B' does not give 'All B are A', though 'Some A are B' does give 'Some B are A'.
- In ranking questions, forgetting to subtract 1 when total = left rank + right rank − 1.