Quantitative Aptitude (Maths, LR & Stats) | CRACKER

Quantitative Aptitude – CRACKER by Kailash Thakur is a chapter-wise book of solved past exam questions for CA Foundation Paper 3. It covers all three parts of the paper: Business Mathematics, Logical Reasoning and Statistics.

The ICAI Study Material has 18 chapters. This book splits them into 28 focused ones, so each topic can be practised on its own. Mathematics of Finance, for example, becomes three chapters: Simple Interest, Compound Interest and Annuity.

The book holds over 2,300 solved questions. Many solutions also show a faster way to the answer, using a shortcut trick or the exact keys to press on a calculator. It is a practice book built for speed and accuracy, with the quicker methods written out step by step.

The Present Publication is the 18th Edition for CA Foundation Paper 3, applicable for the Jan./May 2027 Exams. This book is authored by Kailash Thakur, with the following noteworthy features:

• Solved Past Exam Questions, Chapter-wise: Memory-based questions from past exams are sorted by chapter. Most chapters cover more than ten years of past exams, and every chapter goes right up to the May 2026 exam. Questions are tagged with their source, such as [Jan. 2026].
• September 2026 Exam, Solved in Full: The full September 2026 paper is solved question by question at the end of the book, with suggested answers, tricks and calculator steps. Its match-the-following questions are worked out pair by pair.
• Shortcut Tricks: Many solutions show a quicker route, marked 'Tricks'. The one used most is GBC (Go by Choices): test the given options against the question instead of solving it in full. Other tricks include putting simple numbers in place of letters. Some questions show two routes: a quick trick and the detailed method.
• Calculator Tricks: Many solutions list the exact calculator keys to press, such as %, GT, M+ and MRC. Steps are written key by key, down to how many times to press '='. They cover heavy steps such as large powers, compound interest and annuity values, percentage changes and running totals. Indices, Simple Interest, Compound Interest and Annuity also teach calculator steps in their opening notes.
• Selected RTPs & MTPs Issued by ICAI: Selected questions from ICAI's Revision Test Papers (RTPs) and Mock Test Papers (MTPs) sit alongside the past exam questions. Tags name the series, such as [MTP Jan. 2025] or [RTP May 2026]. They run from the September 2024 series to the September 2026 series. When an exam question is similar to an RTP or MTP question, its tag says so.
• Additional Questions in Selected Chapters: Calculus (Limit & Continuity) and Sampling Theory of Estimation each carry an extra set of Model Exam Questions (For Practice), with an answer key. Together, they add over 200 multiple-choice questions.
• Chapter-wise Marks Distribution of Past Exams: A table at the front shows the marks each chapter carried in every exam from June 2023 to September 2026. The exams sit side by side, with an average for each chapter, so changes from one exam to the next are easy to spot.
• Chapter-wise Mapping with ICAI Study Material: A second table links each chapter of the book to the matching chapter of the ICAI Study Material, by chapter number.

The book spans 28 chapters organised under the three components of Paper 3, with the largest question banks concentrated in the highest-weightage chapters:

Front Tables

• Chapter-wise Marks Distribution
• Chapter-wise Comparison with Study Material

Business Mathematics (Chapters 1 to 15)

• Ratio & Proportion
• Indices
• Logarithm
• Linear Equation
• Quadratic Equation
• Inequalities
• Mathematics of Finance: Simple Interest
• Mathematics of Finance: Compound Interest
• Mathematics of Finance: Annuity
• Permutations and Combinations
• Sequence & Series
• Sets, Function and Relation
• Calculus (Limit & Continuity)
• Differential Calculus
• Integration

Logical Reasoning (Chapters 16 to 19)

• Number Series, Coding & Decoding
• Direction Tests
• Seating Arrangement
• Blood Relations

Statistics (Chapters 20 to 28)

• Description of Data
• Central Tendency
• Measures of Dispersion
• Probability
• Probability (Theoretical) Distribution
• Sampling Theory of Estimation
• Correlation
• Regression Analysis
• Index Numbers

Solved Paper: September 2026 (Suggested Answers)

The structure of the book is as follows:

• Concept Notes: Most chapters open with concept notes: definitions, key formulae and rules, often with solved examples. Some chapters sort problems by type, and the reasoning chapters add pointers, such as the Golden Rules for seating arrangements.
• Practice Sets: In Calculus (Limit & Continuity) and Sampling Theory of Estimation, the Model Exam Questions and their answer key come next, before the past exam questions.
• Question Bank: Every chapter has a bank of past exam questions. Each question is followed straight away by its solution. Where several questions share one set of facts, the facts are given once and the questions follow.
• Solution Steps: Each solution gives the answer. Calculation questions usually show the working step by step, often starting from the formula used. Short notes add tips, such as when a quick check of the options is enough.
• Diagrams: Direction, seating and blood relation solutions often use diagrams, such as route maps, seating plans in rows and circles, and family trees.