General Studies
GDP Components Mnemonic — Remember India's GDP sectors as "MASI": Manufacturing, Agriculture, Services, Industry. Services (~55%) dominate, Agriculture (~15%) declining, helps recall economic structure quickly.
Current Account vs Capital Account — "GIST" for Current: Goods, Income, Services, Transfers (trade-related). Capital account has "FAI": Foreign investment, Assets, International borrowing (investment-related).
Types of Inflation Mnemonic — "CDS Player": Cost-push (supply shock), Demand-pull (excess demand), Stagflation (stagnation + inflation). Most exam questions test demand-pull vs cost-push distinction.
Five-Year Plan Fathers — "Nehru Made Plans, Became PM": 1st Plan (1951) started under Nehru, Mahalanobis Model in 2nd Plan (1956). NITI Aayog replaced Planning Commission in 2015.
Tamil Nadu Districts Trick — 38 districts (as of 2023): Remember newest additions chronologically—Chengalpattu, Kallakurichi, Ranipet, Tenkasi, Tirupathur (2019-20 additions) for current affairs questions.
History, Culture, Heritage & Socio-Political Movements in Tamil Nadu
Sangam Age Periods — "மூன்று சங்கம்" (Three Sangams): 1st Madurai (9990 years—mythical), 2nd Kapadapuram (3700 years), 3rd Madurai (1850 years). Only 3rd Sangam literature survives.
Major Dravidian Parties Timeline — "Justice DK AD ADMK": Justice Party (1916), DK (1944 Periyar split), DMK (1949 Anna split), ADMK (1972 MGR split). Remember founding leaders for chronology.
Pallava Temple Evolution — "Rock Cut → Monolith → Structural": Mahendravarman (rock-cut), Narasimhavarman (monolith—Rathas), Rajasimha (structural—Kailasanatha). Evolution shows architectural progression.
Chola Bronze Trinity — "Nataraja Poses 3-Way": Nataraja (cosmic dance), Ardhanarisvara (Shiva-Parvati union), Somaskanda (family form). 10th-11th century peak under Rajaraja-Rajendra Cholas.
Tamil Freedom Fighters Mnemonic — "SUVC": Subramania Bharati (poet-revolutionary), VOC Chidambaram (Swadeshi Steam), Vanchinathan (assassinated Ashe 1911), Rajaji C (1st Indian Governor-General). Core figures for prelims.
Bhakti Movement Saints — "Nayanars-Shiva, Alvars-Vishnu": 63 Nayanars (including Appar, Sambandar, Sundarar), 12 Alvars (including Andal—only woman). 6th-9th century CE, devotional poetry revolution.
Madurai Sultanate Years — "1335-1378" (43 years only). Remember Malik Kafur invaded 1311, but sultanate existed briefly after Vijayanagara rise. Short-lived Islamic rule in Tamil region.
Aptitude and Mental Ability
Divisibility Rules Quick Check — Divide by 3/9: sum digits. By 4: last 2 digits. By 6: divisible by both 2&3. By 8: last 3 digits. By 11: alternating digit sum difference divisible by 11.
HCF-LCM Product Rule — Product of two numbers = HCF × LCM. If two numbers and HCF given, find LCM instantly. If one number and both HCF-LCM given, find second number directly.
Percentage-Fraction Shortcuts — Memorize: 12.5%=1/8, 16.66%=1/6, 20%=1/5, 25%=1/4, 33.33%=1/3, 40%=2/5, 62.5%=5/8, 66.66%=2/3, 75%=3/4. Converts word problems to fraction calculations instantly.
Time-Speed-Distance Triangle — Draw triangle: Distance (top), Speed and Time (bottom). Cover what you want; remaining shows formula. Distance=Speed×Time, Speed=D/T, Time=D/S. Visual memory aid.
Simple Interest One-Liner — SI = (P×R×T)/100. If principal doubles, time = 100/Rate. If amount becomes 3× principal, time = 200/Rate. Quick doubling/tripling time calculations.
Compound Interest Trick — For 2 years: CI - SI = (SI²)/(100×Principal). Difference between CI and SI helps find rate or principal when other values given. Works only for 2-year problems.
Number Series Patterns — Check differences first, then ratio, then squares/cubes. Common: +prime numbers, ×n±1, perfect squares±small number, Fibonacci variants. 80% series use these four patterns.
Work-Time Formula — If A completes in 'a' days, B in 'b' days, together = (a×b)/(a+b) days. For three persons, find LCM of individual days, assign efficiency units, sum them.
Calendar Quick Day Finding — Odd Days: 1 year=1 odd day, leap=2 odd days. Century: 1600/2000=0, 1700/2100=5, 1800/2200=3, 1900/2300=1 odd days. Sum and divide by 7 for day.
Dice Opposite Faces Sum — Standard dice: opposite faces always sum to 7 (1-6, 2-5, 3-4). In visual reasoning, if three faces visible sum to X, hidden three sum to (21-X).
Ratio Multiplication Shortcut — To combine ratios A:B and B:C, make middle term equal. Example: 2:3 and 4:5 → multiply first by 4, second by 3 → 8:12:15. Works for three-way ratio problems.
Data Interpretation Percentage Base — When comparing years, identify base year clearly. Percentage increase from base ≠ percentage decrease to base (use formula: change/original×100). Avoid reversal trap.