Divisibility Rules of 11, 12 and 13

Duration: 11 min

This video lesson is available to enrolled students.

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Inside: a video lesson and guided study material.

Module outline

  1. About the Course: About the Course
  2. Paper-1 & 2 | Basic Numeracy: अनुपात और समानुपात / Ratio and Proportion, Divisibility Rules, मिश्रण और एलिगेशन / Mixture and Alligation, Permutation and Combination, Logarithm, संख्या पद्धति / Number System, महत्तम समापवर्तक और लघुत्तम समापवर्त्य / HCF and LCM, Sequence and Series (Series), समय, चाल और दूरी / Time, Speed and Distance, प्रतिशत / Percentage, औसत / Average, घन क्षेत्रमिति / Solid Mensuration, Age Problems, Arithmetic, Statistics, Probability, लाभ, हानि और बट्टा / Profit, Loss and Discount, साधारण और चक्रवृद्धि ब्याज / Simple and Compound Interest, Partnership, Speed Mathematics and Basic Mathematics, Algebra, सरलीकरण, घातांक और करणी / Simplification, Indices and Surds, समय और कार्य / Time and Work, Pipe and Cistern, RSSB Specific Videos - Basic Numeracy, समुच्चय, संबंध, फलन और विविक्त गणित / Sets, Relations, Functions and Discrete Mathematics, संख्या पद्धति और संख्या सिद्धांत / Number Systems and Number Theory, निर्देशांक ज्यामिति, सदिश और त्रिविमीय ज्यामिति / Coordinate Geometry, Vectors and 3D Geometry, बहुपद, समीकरण और सम्मिश्र संख्याएँ / Polynomials, Equations and Complex Numbers
  3. Paper-1 & 2 | Data Interpretation: आँकड़ा निर्वचन / Data Interpretation
  4. Paper-1 & 2 | General Mental Ability: Mental Ability, RSSB Specific Videos - Mental Ability
  5. Paper-1 & 2 | Logical Reasoning and Analytical Ability: श्रेणी / Series, कूट लेखन एवं कूट वाचन / Coding-Decoding, Data Sufficiency, अशाब्दिक तर्क / Non-Verbal Reasoning, Syllogisms, बैठक व्यवस्था एवं पहेलियाँ / Seating Arrangement and Puzzles, रक्त संबंध / Blood Relations, दिशा एवं दूरी / Direction and Distance, Analytical Reasoning (Counting Figures Reasoning), गणितीय संक्रियाएँ एवं लुप्त संख्या / Mathematical Operations and Missing Numbers, कैलेंडर एवं घड़ी / Calendar and Clock, Clock, घन, पासा एवं आकृतियों की गिनती / Cubes, Dice and Figure Counting, वेन आरेख, न्याय वाक्य एवं असमानता / Venn Diagrams, Syllogism and Inequalities, सादृश्यता एवं वर्गीकरण / Analogy and Classification, क्रम एवं रैंकिंग / Order and Ranking, कथन आधारित तार्किक विवेचन / Statement-Based Reasoning, Data Arrangement, वर्णमाला एवं संख्या परीक्षण / Alphabet and Number Test, Crypt Arithmetic
  6. Paper-1 & 2 | Decision Making and Problem Solving: आँकड़ों की पर्याप्तता एवं निर्णय क्षमता / Data Sufficiency and Decision Making
  7. Paper-1 | General Science: वैज्ञानिक उपलब्धियाँ और अनुसंधान / Scientific Achievements and Research, Biology, Chemistry, RSSB Specific Videos
  8. Paper-1 | General Awareness: राज्य विशेष सामान्य ज्ञान / State-Specific General Knowledge, समसामयिकी / Current Affairs
  9. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Combinational Circuit, Sequential Circuits
  10. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Calculus, Relational Algebra, SQL, NoSQL
  11. Paper-2 | Data Structures & Algorithms: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Algorithm Analysis, Sorting Algorithms, Intro to Compilers, Hashing
  12. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, Data Link Layer - Ethernet, DLL: Error Control, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Application Layer, Hardware basics, Network Security, Ethical Hacking
  13. Paper-2 | Operating Systems: Introduction to OS, Process Management, Memory Management, File Management, Deadlock
  14. Paper-2 | Computer Organization and Architecture: Basics of COA, Floating Point Rep, Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations, Programming the Basic Computer, Number System, Number Representation
  15. Paper 2 | System Analysis and Design: Fundamentals of Systems and Information Systems, Fundamentals of Software Engineering, SDLC and Development Approaches, Software Documentation and Software Requirements Specification (SRS), SDD and Quality Assurance, Security, Risk Management & Maintenance, Software Testing
  16. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Paper 2 | OOPS , C++ , JAVA: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  18. Paper 2 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  19. Emerging Trends and AI: Emerging Tech Trends, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection
  20. Paper-2 | Data Processing (Ms-Office): MS Office Applications, कंप्यूटर सॉफ़्टवेयर / Computer Software, ऑपरेटिंग सिस्टम / Operating System, वर्ड प्रोसेसिंग (MS Word) / Word Processing (MS Word), प्रेज़ेंटेशन (MS PowerPoint) / Presentation Software (MS PowerPoint)
  21. Paper-2 | Internet and Web Technologies: HTML Basics, CSS, XML, JavaScript-Basics, Internet Fundamentals, Protocols & Services, Web Publishing & Hosting, Server Side & Security, Emerging Technologies, Terms & Abbreviations, Cyber Threats and Malware Attacks, Role of Internet and Web Services, Security in Mobile and Wireless Computing, साइबर सुरक्षा / Cyber Safety and Security, कंप्यूटर नेटवर्क / Computer Networks
  22. Paper 2 | Pedagogy: वृद्धि और विकास / Growth and Development, विकास के सिद्धांत / Theories of Development, Concept of Pedagogy, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, आकलन और मूल्यांकन / Assessment and Evaluation, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020
  23. Live Classes: RSSB Live Sessions
  24. Paper 1 - Full Mock Tests:
  25. Paper 2 - Full Mock Tests:
  26. BCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video provides a comprehensive overview of divisibility rules for numbers 2 through 13, presented by an instructor in a screen recording format. The lecture begins with a colorful, hand-drawn wheel diagram that visually organizes the rules for divisibility by 2, 3, 4, 5, 6, 9, and 10, using examples and key phrases like 'ends in' and 'sum of the digits'. The presentation then transitions to a more formal slide format, where the instructor explains the rule for divisibility by 11, which involves subtracting the last digit from the number formed by the remaining digits, and demonstrates this with examples like 286 and 14641. The video continues with the rule for divisibility by 12, which is based on the principle that a number is divisible by 12 if it is divisible by both 3 and 4, illustrated with the numbers 648 and 524. A key concept introduced is that if a number is divisible by a composite number, it is also divisible by all of its factors, with examples for 6 and 12. The final segment covers the rule for divisibility by 13, which requires adding four times the last digit to the remaining number, demonstrated with the example 5061. The video concludes with a 'Thanks for Watching' screen.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title slide displaying 'DIVISIBILITY RULES' over a background of scattered numbers. It then transitions to a colorful, hand-drawn circular diagram titled 'DIVISIBILITY RULES'. This diagram is divided into sections for different numbers, each explaining a rule. For example, the rule for 2 is 'is an even number', for 5 it's 'ends in 0 or 5', and for 9 it's 'the sum of the digits is divisible by 9'. The instructor, Yash Jain Sir, is visible in a small window, explaining the concepts. The diagram also includes a section for 6, stating it is 'divisible by 2 AND 3'. The visual style is highly illustrative and engaging, using bright colors and arrows to connect concepts.

  2. 2:00 – 5:00 02:00-05:00

    The video shifts to a new slide titled 'Another Rule For 11'. The rule is stated as: 'Subtract the last digit from a number made by the other digits.' The instructor demonstrates this with the example 286: 28 - 6 = 22, and since 22 is divisible by 11, 286 is also divisible by 11. He then applies the rule to 14641: 1464 - 1 = 1463, then 146 - 3 = 143, then 14 - 3 = 11, and since 11 is divisible by 11, 14641 is also divisible by 11. The instructor uses red ink to write out the steps on the slide, emphasizing the process of repeated application.

  3. 5:00 – 10:00 05:00-10:00

    The next slide, titled '12', explains that a number is divisible by 12 if it passes both the divisibility rules for 3 and 4. The instructor demonstrates this with the number 648: the sum of its digits (6+4+8=18) is divisible by 3, and the last two digits (48) form a number divisible by 4, so 648 is divisible by 12. For 524, the sum of digits (5+2+4=11) is not divisible by 3, so 524 is not divisible by 12. The video then introduces a new concept: 'Factors Can Be Useful'. It explains that if a number is divisible by a composite number, it is also divisible by each of its factors. For example, if a number is divisible by 12, it is also divisible by 2, 3, 4, and 6. The instructor writes the factors of 12 as {1, 2, 3, 4, 6, 12}.

  4. 10:00 – 11:06 10:00-11:06

    The final topic is the divisibility rule for 13. The rule is to 'Add four times the last digit to the remaining leading truncated number.' The instructor demonstrates this with the number 5061: 506 + (1*4) = 510, then 51 + (0*4) = 51, then 5 + (1*4) = 9. Since 9 is not divisible by 13, 5061 is not divisible by 13. The instructor then corrects the example, showing that for 5061, the correct calculation is 506 + (1*4) = 510, then 51 + (0*4) = 51, then 5 + (1*4) = 9, which is not divisible by 13. The video ends with a 'THANKS FOR WATCHING' screen.

The video presents a structured and progressive lesson on divisibility rules, moving from a visually engaging overview to detailed, step-by-step demonstrations. It begins with a comprehensive diagram for basic rules (2, 3, 4, 5, 6, 9, 10), establishing a foundation. The core of the lesson focuses on more complex rules for 11 and 13, using a consistent method of explanation: stating the rule, providing a clear example, and showing the calculation process. A key pedagogical point is the introduction of the concept that divisibility by a composite number implies divisibility by its factors, which is a powerful shortcut for students. The instructor's use of a screen recording with on-screen annotations allows for a clear, focused presentation of the mathematical logic, making the content accessible for revision and learning.

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