Grade B Posts (Gazetted):
  Assistant Audit Officer (AAO): ₹47,600-₹1,51,100 (Indian Audit & Accounts)
  Assistant Accounts Officer: Same pay, Finance Ministry
  Assistant Section Officer: Ministry of External Affairs, CSS, CSCS

Grade C Posts:
  Inspector (Income Tax): CBI, Income Tax
  Inspector (Central Excise): CBIC
  Sub-Inspector: CBI, NIA, other agencies
  Junior Statistical Officer: M/o Statistics and PI
  Auditor: CGDA, various ministries
  Upper Division Clerk: Various central ministries
  Tax Assistant: CBDT, CBIC
  Lower Division Clerk (LDC)

Most sought after: 
  AAO (highest pay + interesting audit work)
  Income Tax Inspector (field work + good posting)
  CSS (Central Secretariat Service — work with top bureaucracy)

Tier I — Preliminary (100 marks, 60 minutes, online)
  General Intelligence & Reasoning:  25 questions, 50 marks
  General Awareness:                  25 questions, 50 marks
  Quantitative Aptitude:              25 questions, 50 marks
  English Comprehension:              25 questions, 50 marks
  
  Negative marking: -0.50 per wrong answer
  Cutoff typically: 130-145 for General category
  
Tier II — Mains (online, new pattern from 2023)
  Session 1: Maths + Reasoning (2h 30min, combined paper)
  Session 2: English (2h 15min, language and comprehension)
  Session 3: Statistics OR General Studies (Finance/Economics) — only for specific posts
  
Tier III — Descriptive (pen and paper)
  Essay (250 words) + Letter/Application (150 words)
  60 minutes, 100 marks
  Only for posts requiring language skills

Tier IV — Data Entry/Computer Proficiency
  For specific posts (Data Entry Operator, etc.)

Divisibility rules (must know instantly):
  2: Last digit even
  3: Sum of digits divisible by 3
  4: Last 2 digits divisible by 4
  6: Divisible by 2 AND 3
  8: Last 3 digits divisible by 8
  9: Sum of digits divisible by 9
  11: Alternating sum of digits divisible by 11
       (132: 1-3+2 = 0, divisible by 11 ✓)

HCF and LCM:
  HCF × LCM = Product of two numbers (for exactly 2 numbers)
  HCF of fractions: HCF of numerators / LCM of denominators
  LCM of fractions: LCM of numerators / HCF of denominators
  
Powers and indices:
  (aᵐ)ⁿ = aᵐⁿ
  aᵐ × aⁿ = aᵐ⁺ⁿ
  aᵐ ÷ aⁿ = aᵐ⁻ⁿ
  Cyclicity of units digit: Find pattern (powers of 2: 2,4,8,6,2,4,8,6...)

Percentage shortcuts:
  x% of y = y% of x (powerful symmetry)
  15% of 80 = 80% of 15 = 12 ✓
  
  % increase: (new-old)/old × 100
  % decrease: same formula, will be negative
  
  Successive discounts a% and b%: net = a + b - ab/100
  Price after two 10% discounts: 10+10-1 = 19% discount (not 20%)

Ratio and Proportion:
  If a:b = c:d, then ad = bc
  Compound ratio: multiply individual ratios
  Variation: Direct (y=kx), Inverse (y=k/x)

Profit and Loss:
  CP = Cost Price, SP = Selling Price
  Profit% = (SP-CP)/CP × 100
  SP = CP × (100+P%)/100
  
  Marked Price (MP) and Discount:
    SP = MP × (100-D%)/100
    Profit even after discount: Need SP > CP
  
  Dishonest dealer who uses false weight:
    Profit% = (true weight - false weight)/false weight × 100

Time Speed Distance:
  D = S × T
  Average speed = 2xy/(x+y) when equal DISTANCES at x and y
  Average speed = (x+y)/2 when equal TIME at x and y
  
  Train problems:
    Crosses pole: Time = Length/Speed
    Crosses platform: Time = (Length + Platform)/Speed
    Two trains meeting: use relative speed
      Same direction: relative speed = S₁ - S₂
      Opposite direction: relative speed = S₁ + S₂

Time and Work:
  1/a + 1/b = 1/T → T = ab/(a+b)
  Pipes: Inlet - Outlet per hour = 1/T
  Efficiency: Worker with more efficiency → less time

Circle properties (SSC CGL favourite):
  Angle in semicircle = 90°
  Angles in same segment are equal
  Angle at centre = 2 × angle at circumference
  Opposite angles of cyclic quadrilateral = 180°
  Tangent perpendicular to radius at point of contact
  Two tangents from external point are equal
  
Triangles:
  Sum of angles = 180°
  Exterior angle = sum of two non-adjacent interior angles
  Area = ½ × base × height = √[s(s-a)(s-b)(s-c)] (Heron's)
  
  Special triangles worth memorising:
    3-4-5, 5-12-13, 8-15-17, 7-24-25 (right triangles)
    Equilateral: All sides equal, all angles 60°, area = √3/4 × a²

Mensuration (very high weightage in SSC):
  Rectangle: Area = lb, Perimeter = 2(l+b)
  Circle: Area = πr², Circumference = 2πr
  Sphere: Volume = 4πr³/3, Surface area = 4πr²
  Cylinder: Volume = πr²h, Curved SA = 2πrh, Total SA = 2πr(r+h)
  Cone: Volume = πr²h/3, Slant height l = √(r²+h²), CSA = πrl
  Cube: Volume = a³, Surface area = 6a²
  Cuboid: Volume = lbh, Surface area = 2(lb+bh+hl)

High-scoring topics (easy marks):
  
Analogy: Find same relationship
  Doctor : Patient :: Teacher : Student (service provider : recipient)
  
Classification (odd one out):
  Find the one that doesn't belong to same category
  
Series completion:
  Number series: Find pattern (arithmetic, geometric, squares, cubes)
  Letter series: Alphabetical position based
  
Coding-Decoding:
  Letter coding: COLD = DPME (each letter +1)
  Number coding: Build decoder from given example
  
Sitting arrangement:
  Draw it — don't try to solve in head
  Circular arrangement: Fix one person, arrange rest relative
  
Blood relations:
  Draw family tree, never rely on memory alone
  
Direction and distance:
  Always draw the path on paper
  Use Pythagoras for diagonal distances
  
Venn diagram:
  Read carefully — "only X", "X and Y but not Z" are different
  
Mirror/Water image:
  Mirror: Left-right reversed
  Water: Top-bottom reversed
  Clock time: Mirror image of time: 11:60 - original time

History (always 3-5 questions):
  Freedom struggle: 1857, INC formation, all major movements
  Mughal Empire: Akbar's administration, Aurangzeb policies
  Ancient India: Mauryan Empire, Ashoka, Gupta period

Geography (3-5 questions):
  Rivers: Origin, tributaries, dams on them
  National Parks: State-wise list
  Soils: Alluvial, black, red, laterite — states and crops
  Passes: Nathu La, Shipki La, Zoji La, Banihal — states

Polity (3-5 questions):
  Fundamental Rights, DPSPs, President's powers
  Article numbers of important provisions
  Constitutional bodies: CAG, EC, UPSC, Finance Commission

Economy (2-4 questions):
  Budget terms: Fiscal deficit, revenue deficit, GDP components
  RBI functions, monetary policy tools
  Banking terms: CRR, SLR, Repo Rate

Science (4-6 questions):
  Biology: Human body systems, diseases (viral/bacterial)
  Chemistry: Elements, compounds, reactions in daily life
  Physics: SI units, laws, inventors

Current affairs (3-5 questions):
  Sports: Winners of major tournaments
  Government schemes: Names, objectives, launch date
  Awards: Bharat Ratna, Padma, Nobel laureates
  International: G20, BRICS, UN resolutions

Error Identification (Spotting the Error):
  Subject-verb agreement
    Neither/Either + singular verb
    Collective nouns (committee, team) can be singular or plural
    "A number of" + plural verb; "The number of" + singular
  
  Tense consistency: Don't switch tenses without reason
  Prepositions: Common errors — "afraid of", "consist of", "interested in"
  Articles: a (consonant sound), an (vowel sound), the (specific)

Vocabulary:
  One word substitution: Practice 200-300 common ones
  Synonyms/Antonyms: Context-based understanding, not memorisation
  Idioms: Practice 100 common idioms
  
  Commonly confused words:
    Affect (verb) vs Effect (noun)
    Then (time) vs Than (comparison)
    Its (possessive) vs It's (it is)
    Principle (rule) vs Principal (head/main)

Reading Comprehension:
  Always read the questions first
  Find location in passage, then read that section
  Don't bring outside knowledge — answer from passage only
  Tone/inference questions: Think about what writer implies

3-Month Intensive Plan:

Month 1: Build Foundation
  Quant: Number system, percentage, ratio, profit-loss (HW daily)
  Reasoning: Analogy, series, coding-decoding, blood relations
  English: Grammar rules, 30 vocab words daily
  GK: Start reading The Hindu daily, 1 static GK chapter daily

Month 2: Core Practice
  Quant: TSD, time-work, geometry, mensuration
  Reasoning: Puzzles, seating arrangement, direction-distance
  English: Comprehension practice, error spotting
  GK: History, Polity, Geography (Laxmikanth for Polity essential)
  Mock: Tier I mock every Sunday, analyze thoroughly

Month 3: Revision + Mocks
  Daily: 2 topic tests + 1 full mock (Tier I)
  Week 1-2: Revise weak areas from mock analysis
  Week 3-4: Final revision of formulas, GK notes, vocabulary
  Strategy: Attempt 85-90 questions, 85%+ accuracy target

Mock test analysis framework (after every mock):
  ✓ Time per question (did you rush/spend too long?)
  ✓ Wrong questions — concept error or silly mistake?
  ✓ Skipped questions — were they solvable with more time?
  ✓ Section-wise performance — where to improve?
  Never look at answer, always understand WHY you were wrong

Books:
  Quant: Rakesh Yadav 7300+ or Arihant SSC CGL
  Reasoning: Kiran's Reasoning
  English: Wren & Martin (grammar), Word Power Made Easy (vocab)
  GK: Lucent's General Knowledge (static), monthly current affairs

Online:
  Official SSC website for notifications and answer keys
  Testbook, Adda247 for mock tests and current affairs
  YouTube: Rakesh Yadav classes for Maths, study channels for current affairs

Previous papers:
  Last 5 years Tier I and II papers are non-negotiable
  Many questions are repeated with minor variations
  SSC CGL 2019, 2020, 2021, 2022 papers in detail