Numerical Aptitude
- Divisibility by 11 Trick — Alternate digit sum: subtract sum of digits at odd positions from even positions. If result is 0 or multiple of 11, number is divisible by 11. Example: 121 → (1+1)−2=0, divisible.
- Square of 5-ending numbers — For numbers ending in 5: multiply first digit(s) by next consecutive number, append 25. Example: 85² = 8×9=72, answer=7225. Works instantly for 15²,25²,35²...95².
- Percentage to Fraction shortcuts — 12.5%=⅛, 16.67%=⅙, 20%=⅕, 25%=¼, 33.33%=⅓, 37.5%=⅜, 62.5%=⅝, 87.5%=⅞. Memorize these eight for instant calculation without decimal multiplication.
- Compound Interest Quick Formula — For small rates over 2 years: CI−SI = (SI×R)/200, where R is rate%. Saves time when calculating difference between simple and compound interest.
Logical Reasoning
- Blood Relation Gender Markers — A-ending = Always female (Niece, Grandmother, Aunt, Daughter, Sister, Granddaughter). No A-ending check carefully (Uncle, Father, Brother, Grandson, Nephew, Son). Quick gender identification in family tree problems.
- Direction Sense: WENS Clock Rule — Face any direction. Left turn = anticlockwise, Right turn = clockwise on WENS circle (West-East-North-South). 90° right = next letter clockwise; 180° = opposite letter.
- Syllogism: "Some+All" Rule — When premise has "Some A are B" + "All B are C", conclusion is always "Some A are C" (definite). But "All+All" gives "All", "Some+Some" gives no definite conclusion.
- Coding-Decoding: Letter Positions — EJOTY = 5,10,15,20,25 (multiples of 5). Quick reference points to calculate letter shifts forward/backward. A=1, Z=26 as anchors.
Data Interpretation
- Percentage Change Formula — % increase = (Difference/Original)×100. Common trap: % decrease then increase by same % does NOT return to original. Example: 100→20% down=80→20% up=96, not 100.
- Ratio Simplification — For comparing multiple ratios, convert all to same second term (LCM method) or decimal. Example: 2:3, 3:4, 5:6 → make denominators 12 → 8:12, 9:12, 10:12.
- Bar Graph Time-Saver — Calculate approximate values using visual estimation for elimination. Exact calculation only for final 2 options. Saves 40% time in data-heavy questions.
General Aptitude and Reasoning
- Calendar: Odd Days Concept — Ordinary year=1 odd day, Leap year=2 odd days. For day calculation: find total odd days, divide by 7, remainder gives day. 0=Sunday, 1=Monday...6=Saturday.
- Clock Angle Formula — Angle = |11M−60H|/2 degrees, where H=hour, M=minutes. If result >180°, subtract from 360°. Right angle at 3:00 gives 90° verification.
Lakshadweep Specific
- Lakshadweep Islands: "ABCKAM" Mnemonic — Amini, Bangaram, Chetlat, Kavaratti (capital), Agastrophy(lost), Minicoy. Covers major inhabited islands for administrative questions.
- Coconut Product Trinity — CTC: Copra (dried kernel), Toddy (sap drink), Coir (fiber from husk). Three primary coconut economy products of Lakshadweep for economic questions.
- Minicoy Language — Mahl (Dhivehi script) only in Minicoy; rest of Lakshadweep speaks Malayalam. Minicoy culturally closer to Maldives. Remember: Minicoy=Mahl, different from mainland.