General Studies and Mental Ability
Divisibility by 11 — Alternating digit sum rule: subtract sum of odd-position digits from even-position digits; if result is 0 or multiple of 11, number is divisible by 11. Quick mental check for large numbers.
BODMAS Trap — Division and Multiplication have EQUAL priority (left-to-right); Addition and Subtraction have EQUAL priority (left-to-right). Don't blindly do all M before D or all A before S.
Calendar Day Formula — Odd days concept: count remainder when total days ÷ 7. Leap year = 2 odd days, normal year = 1 odd day. Anchor: 1-Jan-2000 was Saturday.
Sangam Ages Chronology — "Early Chera Chola, Middle Pandya, Late Together" — Early Sangam (Cheras, Cholas dominate), Middle (Pandyas rise), Late (all three kingdoms documented together). 300 BCE–300 CE span.
Indian Monsoon Months — "JJAS" = June, July, August, September (SW Monsoon). "ON-DJ" = October-November (NE Monsoon retreating), December-January (winter). Covers 75% questions on rainfall patterns.
Constitutional Amendment Numbers — 42nd = "Mini Constitution" (1976, added Fundamental Duties, Socialist-Secular); 44th = removed Right to Property from Fundamental Rights (1978); 52nd = Anti-Defection Law (1985); 73rd-74th = Panchayati Raj & Urban Bodies (1992).
Fundamental Rights Articles — "FARCE" = Freedom (19), Against exploitation (23-24), Right to Constitutional remedies (32), Cultural & Educational (29-30), Equality (14-18). Articles 14-32 span all six FR categories.
Five-Year Plan Priorities — 1st Plan = Agriculture, 2nd = Industry (Mahalanobis model), 3rd = Self-reliance, 5th = "Garibi Hatao", 8th = Human development, 12th = "Faster, Sustainable, Inclusive Growth". Match plan number to decade.
Latitude-Climate Zones — Tropic of Cancer (23.5°N) cuts through 8 Indian states: "GRAM CHAMP" = Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram (west to east).
UN Specialized Agencies — "WHO FAIML" = WHO (health), FAO (food/agriculture), ILO (labor), IMF (monetary), WB (development). Remember UNESCO (education/culture), UNICEF (children) separately as most-asked.
Indian National Movement
1857 Rebellion Centers — "DMBLK" = Delhi (Bahadur Shah), Meerut (start point), Bareilly (Khan Bahadur), Lucknow (Begum Hazrat Mahal), Kanpur (Nana Sahib), Jhansi (Laxmibai). Six major epicenters, British suppressed by 1858.
Gandhi's Satyagrahas Sequence — Champaran (1917, indigo), Kheda (1918, tax), Ahmedabad (1918, mill workers), then NCM (1920), Salt (1930), Quit India (1942). Mnemonic: "CKA-NaSaQu" for chronology.