Part 1 - Short Tricks to check Divisibility by 7 & 13

Duration: 12 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 | Fundamentals of Computer: Basics of COA, Number System, Floating Point Rep, Number Representation
  10. Paper - 2 | Digital Logic Systems: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits
  11. Paper-2 | Operating Systems: Introduction to OS, Process Management, CPU Scheduling, Process Synchronization, Deadlock, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Linux OS, Distributed Systems
  12. Paper-2 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, Relational Algebra, SQL, Relational Calculus, File Organization & Indexing, Transaction Management, Concurrency Control
  13. Paper-2 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing
  14. Paper-2 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  15. Paper 2 | Oops, C++, Java: Language Design, OOPS with C++, Java, .Net Programming, Java Fundamentals
  16. 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
  17. Paper 2 | Emerging Trends and AI: Emerging Tech Trends, कंप्यूटर के मूल सिद्धांत / Computer Fundamentals, व्यापार, विपणन एवं उपभोक्ता संरक्षण / Trade, Marketing and Consumer Protection, कंप्यूटर नेटवर्क / Computer Networks
  18. Paper-2 | Algorithms: Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Advanced Algorithms
  19. Paper 2 | Data Communication and Network Security: Introduction to CN, Data Communication, DLL: Access Control, DLL: Flow Control, DLL: Error Control, Data Link Layer - Ethernet, Net Layer: IPv4 & Proto, Net Layer: IP Addressing, Net Layer:Routing Protocol, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics, Network Security, Ethical Hacking
  20. Paper-2 I Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Testing, Software Maintenance and Configuration Management
  21. Paper-2 | Computer Organization and Architecture: Cache Memory Organization, Input Output Organisation, Instr Formats & Modes, Control Unit Design, Register Transfer and Microoperations
  22. Paper-2 | Web Development: JavaScript-Basics, HTML Basics, CSS, XML
  23. Pedagogy: वृद्धि और विकास / Growth and Development, Concept of Pedagogy, संज्ञानात्मक प्रक्रियाएँ / Cognitive Processes, विकास के सिद्धांत / Theories of Development, समावेशी शिक्षा / Inclusive Education, Experiential Pedagogy, समाजीकरण और जेंडर / Socialisation and Gender, National Education Policy (NEP) 2020
  24. Live Sessions: RSSB Live Sessions
  25. RSSB Paper 1 - Full Mock Tests:
  26. RSSB Paper 2 - Full Mock Tests:
  27. SCI Previous Year Papers:
AI summary & chapters

AI Summary

An AI-generated summary of this video lecture.

This educational video, presented by Yash Jain from Knowledge Gate Eduventures, is a tutorial on divisibility rules for prime numbers, specifically focusing on 7 and 13. The video begins with an introduction to the concepts of LCM (Least Common Multiple) and HCF (Highest Common Factor), using a title card and a classroom-style animation. The main content then transitions to a problem-solving session where the instructor poses the question: "How many of the following numbers are divisible by 7?" The numbers listed are 533, 987, 2996, 532, and 6789. The instructor demonstrates a specific divisibility rule for 7: take the last digit, multiply it by 2, and subtract it from the remaining number. This process is repeated until a small number is obtained, which is then checked for divisibility by 7. The video provides a step-by-step walkthrough for each number, using on-screen calculations to show that 2996 and 532 are divisible by 7, while the others are not. The video concludes by introducing a different rule for divisibility by 13, which involves adding four times the last digit to the remaining number, and demonstrates this rule with the example of 50661. The final frame is a 'Thanks for Watching' message.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying "LCM & HCF" against a digital, data-stream background. It then transitions to a classroom setting with a cartoon teacher and a green chalkboard. The board clearly states "Highest Common Common Factor Factor (HCF)". The instructor, Yash Jain, is visible in a small window in the bottom right corner. The video is branded with the "KG" logo and the name "KNOWLEDGE GATE EDUCATION". This segment establishes the topic of the lecture, which is a foundational concept in mathematics.

  2. 2:00 – 5:00 02:00-05:00

    The video presents a new problem on a yellow background with a pattern of stars and shapes. The on-screen text asks, "Que: How many of the following numbers is divisible by 7 ?" followed by the list of numbers: 533, 987, 2996, 532, 6789. The instructor begins to analyze the first number, 533, by writing a calculation on the screen. He demonstrates the divisibility rule for 7: he takes the last digit (3), multiplies it by 2 (3 x 2 = 6), and subtracts it from the remaining number (53 - 6 = 47). He then checks if 47 is divisible by 7, concluding it is not. This process is repeated for the other numbers.

  3. 5:00 – 10:00 05:00-10:00

    The instructor continues to apply the divisibility rule for 7 to the remaining numbers. For 987, he calculates 98 - (7 x 2) = 98 - 14 = 84, and then 8 - (4 x 2) = 8 - 8 = 0, which is divisible by 7, so 987 is divisible by 7. For 2996, he calculates 299 - (6 x 2) = 299 - 12 = 287, then 28 - (7 x 2) = 28 - 14 = 14, which is divisible by 7, so 2996 is divisible by 7. For 532, he calculates 53 - (2 x 2) = 53 - 4 = 49, which is divisible by 7, so 532 is divisible by 7. For 6789, he calculates 678 - (9 x 2) = 678 - 18 = 660, then 66 - (0 x 2) = 66, which is not divisible by 7. The instructor concludes that three numbers (987, 2996, 532) are divisible by 7.

  4. 10:00 – 12:17 10:00-12:17

    The video transitions to a new topic: divisibility by 13. The on-screen text explains the rule: "Add four times the last digit to the remaining leading truncated number. If the result is divisible by 13, then so was the first number." An example is provided: 50661. The instructor demonstrates the rule: 5066 + (1 x 4) = 5070, then 507 + (0 x 4) = 507, then 50 + (7 x 4) = 50 + 28 = 78, and finally 78 is divisible by 13 (6 x 13 = 78). The video ends with a black screen displaying the text "THANKS FOR WATCHING" in an orange and white box.

The video provides a structured, step-by-step tutorial on applying divisibility rules for prime numbers. It begins by establishing the context of LCM and HCF, then focuses on a practical problem involving divisibility by 7. The instructor clearly explains and demonstrates a specific rule, using on-screen calculations to verify the divisibility of each number in the list. The lesson concludes by introducing a different rule for divisibility by 13, demonstrating its application with a clear example. The progression moves from a general topic to a specific problem, and then to a new, related concept, making it a comprehensive guide for students learning these mathematical shortcuts.

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