Section · UPSC CSE Prelims · Paper II (Qualifying)
CSAT Paper II
UPSC CSE Prelims Paper II (CSAT), concept by concept: quantitative aptitude, logical reasoning and reading comprehension with worked examples and practice questions.
30 articles in this section
30 articles in this section
The official syllabus, topic by topic
Civil Services Aptitude Test (Paper II, Qualifying). Every topic below appears in the order UPSC lists it — the chips under each one are our published notes on it.
33 areas covered
Quantitative aptitude
Basic numeracy: number systems, percentages, ratios, averages, series, time and work, interest, mensuration, permutation and combination, and data interpretation.
Number System for CSATPercentage for CSATRatio and Proportion for CSATAverage for CSATNumber Series for CSATProblems on Ages for CSATTime and Work: Efficiency, the LCM Method and CSAT ShortcutsPipes and Cisterns: Fill, Drain and Net Rate Tricks for CSATSpeed, Time and Distance for CSAT: Trains, Boats and Circular MotionProfit and Loss for CSAT: Percentages, Discounts and Dishonest DealersPartnership for CSAT: Capital, Time and Profit SharingSimple and Compound Interest for CSAT: Formulae and PYQsVenn Diagrams for CSAT: Two-Set and Three-Set ProblemsGeometry and Mensuration for CSAT: PYQs ExplainedPermutation and Combination for CSAT: PYQs ExplainedProgressions for CSAT: AP, GP and HP ExplainedData Interpretation for CSAT: Tables and PYQsLogical reasoning
Coding-decoding, blood relations, direction sense, seating arrangements, syllogisms, data sufficiency, critical reasoning and non-verbal puzzles.
Coding-Decoding for CSAT: Concepts, Patterns and PracticeBlood Relations for CSAT: Family Trees and Coded RelationsDirection Sense for CSAT: Turns, Shadows and Shortest DistanceSeating Arrangement for CSAT: Linear and CircularNumber Ranking and Sequence for CSATCalendar and Clock for CSAT: Odd Days and Hand AnglesCube and Dice for CSATSyllogisms and Statement-Based Questions for CSATData Sufficiency for CSATCritical Reasoning for CSATNon-Verbal Reasoning for CSATPuzzles for CSAT: Seating and ArrangementsReading comprehension
Passage strategies, question types and practice for the qualifying comprehension section.
Puzzles for CSAT: Seating and Arrangements
Solve CSAT puzzles with a fixed method: circular and linear seating, scheduling, floor puzzles, blood relations and truth-value puzzles, with step-by-step worked examples.
CSAT · 29 September 2026 · 10 min read
Non-Verbal Reasoning for CSAT
Master non-verbal reasoning for CSAT Paper II: number series patterns, missing-character matrices, odd-one-out and analogies, with UPSC PYQs and fully solved practice.
CSAT · 29 September 2026 · 8 min read
Critical Reasoning for CSAT
Master critical reasoning for CSAT Paper II: assumptions with the negation test, inferences with contrapositives, conclusions, strengthen-weaken and paradox questions, with solved examples.
CSAT · 29 September 2026 · 9 min read
Data Sufficiency for CSAT
Crack data sufficiency in CSAT Paper II: the four verdicts, the sufficiency-not-solution rule, the alone-first method, classic traps, and practice questions with full solutions.
CSAT · 29 September 2026 · 10 min read
Syllogisms and Statement-Based Questions for CSAT
Master syllogisms for CSAT Paper II: the four categorical forms, the Venn diagram method, valid and invalid argument forms, and statement-based questions, with solved examples.
CSAT · 29 September 2026 · 12 min read
Cube and Dice for CSAT
Master opposite-face rules, the standard dice, painted-cube counting formulas and cut-piece logic for CSAT Paper II, with worked examples and practice questions.
CSAT · 29 September 2026 · 10 min read
Calendar and Clock for CSAT: Odd Days and Hand Angles
Master CSAT calendar and clock questions: odd days, leap years, weekday finding, and the hand-angle formula, with solved UPSC examples.
CSAT · 29 September 2026 · 13 min read
Number Ranking and Sequence for CSAT
Master CSAT rank questions: the total formula, interchanges, middle-person puzzles, and digit sequences, with solved UPSC examples.
CSAT · 29 September 2026 · 12 min read
Seating Arrangement for CSAT: Linear and Circular
Crack CSAT seating arrangement sets: linear rows, circular tables, facing rules, and must-be-true logic, with solved UPSC examples.
CSAT · 29 September 2026 · 13 min read
Direction Sense for CSAT: Turns, Shadows and Shortest Distance
Build reliable direction sense for CSAT: compass turns, shadow logic, and Pythagoras-based shortest distance, with solved UPSC examples.
CSAT · 29 September 2026 · 13 min read
Blood Relations for CSAT: Family Trees and Coded Relations
Learn to crack CSAT blood relation questions with the family-tree method, pointing puzzles, and coded relations, fully solved step by step.
CSAT · 29 September 2026 · 14 min read
Coding-Decoding for CSAT: Concepts, Patterns and Practice
Master the hidden rules behind CSAT coding questions: letter shifts, reversals, number codes, and sentence coding, with solved UPSC examples.
CSAT · 29 September 2026 · 12 min read
Data Interpretation for CSAT: Tables and PYQs
Read tables and charts the fast way: the five computations behind every DI question, percentage traps, per-day averages, and real UPSC PYQ sets solved step by step.
CSAT · 29 September 2026 · 9 min read
Progressions for CSAT: AP, GP and HP Explained
Arithmetic, geometric and harmonic progressions from first principles: formulae, sum shortcuts, bouncing-ball and price puzzles, and real UPSC PYQs solved step by step.
CSAT · 29 September 2026 · 13 min read
Permutation and Combination for CSAT: PYQs Explained
Permutations, combinations and counting rules explained from zero, then applied to real UPSC PYQs: paintings, roads, handshakes, task assignments and selection puzzles.
CSAT · 29 September 2026 · 12 min read
Geometry and Mensuration for CSAT: PYQs Explained
CSAT geometry is about counting figures, tiling shapes and rolling wheels, not long calculations. Learn the formulae, the three question patterns, and solve real UPSC PYQs.
CSAT · 29 September 2026 · 11 min read
Venn Diagrams for CSAT: Two-Set and Three-Set Problems
A Venn diagram turns overlap questions into arithmetic. Learn the inclusion-exclusion rule for two and three sets, then solve real UPSC PYQs on newspapers, magazines and exam results.
CSAT · 29 September 2026 · 12 min read
Simple and Compound Interest for CSAT: Formulae and PYQs
Master Simple and Compound Interest for CSAT Paper II: SI and CI formulae, compounding frequency, the CI-SI difference shortcut, effective rates, with PYQs and practice.
CSAT · 29 September 2026 · 10 min read
Partnership for CSAT: Capital, Time and Profit Sharing
Master Partnership for CSAT Paper II: the capital-time rule, compound partnerships, working-partner commission, missing capital or time, ratio puzzles and PYQs.
CSAT · 29 September 2026 · 11 min read
Profit and Loss for CSAT: Percentages, Discounts and Dishonest Dealers
Master Profit and Loss for CSAT Paper II: cost versus selling price, the same-SP trap, discounts on marked price, dishonest-dealer problems, with PYQs and practice sets.
CSAT · 29 September 2026 · 11 min read
Speed, Time and Distance for CSAT: Trains, Boats and Circular Motion
Master Speed, Time and Distance for CSAT Paper II: average speed, relative speed, train crossings, boats and streams, circular motion, with PYQs and worked examples.
CSAT · 29 September 2026 · 13 min read
Pipes and Cisterns: Fill, Drain and Net Rate Tricks for CSAT
Master Pipes and Cisterns for CSAT Paper II: net rate, the LCM method, closed-early and half-tank patterns, speed-ratio pipes, plus PYQs and practice sets.
CSAT · 29 September 2026 · 10 min read
Time and Work: Efficiency, the LCM Method and CSAT Shortcuts
Master Time and Work for CSAT Paper II: efficiency and the LCM method, combined work, alternate-day schedules, pair problems and PYQs with fully worked solutions.
CSAT · 29 September 2026 · 14 min read
Problems on Ages for CSAT
Problems on ages for CSAT: the constant-difference rule, the k method for ratio ages, past and future ratios, and sum/average of ages, with worked examples and practice MCQs.
CSAT · 29 September 2026 · 11 min read
Number Series for CSAT
Number series for CSAT: the pattern checklist covering AP, GP, squares, cubes, difference ladders, interleaved and Fibonacci series, with worked examples and practice MCQs.
CSAT · 29 September 2026 · 9 min read
Average for CSAT
Average for CSAT: the total trick, weighted averages, replacement shortcuts and sequence averages, with worked examples, traps and practice MCQs.
CSAT · 29 September 2026 · 8 min read
Ratio and Proportion for CSAT
Ratio and proportion for CSAT: simplifying ratios, fourth and mean proportionals, direct and inverse variation, and ratio methods inside ages and partnership questions, with MCQs.
CSAT · 29 September 2026 · 9 min read
Percentage for CSAT
Percentage decoded for CSAT: percent as fraction, percent change, successive increases, reverse percentage and election questions, with worked examples, traps and practice MCQs.
CSAT · 29 September 2026 · 9 min read
Number System for CSAT
The number system is the backbone of CSAT quant: divisibility rules, primes, factors, HCF and LCM, remainders and unit digits explained with worked examples, common traps and practice questions.
CSAT · 29 September 2026 · 11 min read