Short Trick to find HCF by using smallest element

Duration: 10 min

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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 provides a step-by-step tutorial on calculating the Highest Common Factor (HCF) using the 'Least Number' method, which is a variation of the prime factorization technique. The instructor, Yash Jain, begins by introducing the topic and then demonstrates the method with several examples. The first example involves finding the HCF of 6, 12, and 18. The method involves identifying the smallest number among the given numbers (the 'pivot element') and then checking if it divides all other numbers. If it does, it is the HCF. If not, the process is repeated with the next smallest number. The video then applies this method to more complex sets of numbers, such as (8, 16, 20, 28, 44) and (8, 11, 16, 20, 28, 44, 46), consistently demonstrating the process of elimination to find the highest common factor. The video concludes with a final example and a 'Thanks for Watching' screen.

Chapters

  1. 0:00 – 2:00 00:00-02:00

    The video opens with a title card displaying 'LCM & HCF' against a digital background. It then transitions to a lecture slide with a green chalkboard background. The slide is titled '5. HCF using Least Number' and presents the first example: 'HCF (6, 12, 18)'. The instructor, Yash Jain, begins to explain the method, writing the numbers 6, 12, and 18 on the board. He identifies 6 as the smallest number and the 'pivot element' for the method, explaining that the goal is to find the highest common factor by checking divisibility.

  2. 2:00 – 5:00 02:00-05:00

    The instructor continues the first example, demonstrating the 'Least Number' method. He writes '6, 12, 18' and circles the number 6, labeling it the 'pivot element'. He then checks if 6 divides 12 and 18. He writes '6/12 = 2' and '6/18 = 3', indicating that 6 divides both numbers. Since 6 divides all the numbers in the set, he concludes that the HCF is 6, writing 'HCF = 6'. The video then moves to the next example, 'HCF (8, 16, 20, 28, 44)'. He identifies 8 as the pivot element and checks if it divides all other numbers. He writes '8/16 = 2', '8/20 = 2.5', and '8/28 = 3.5', showing that 8 does not divide 20 or 28. He then circles 8 and marks the other numbers with a cross, indicating they are not divisible by 8. He then identifies the next smallest number, 16, as the new pivot element and begins to check its divisibility.

  3. 5:00 – 9:34 05:00-09:34

    The instructor continues with the second example, 'HCF (8, 16, 20, 28, 44)'. He checks if 16 divides 8, 20, 28, and 44, and finds that it does not. He then moves to the next smallest number, 20, and checks its divisibility, finding it fails. He continues this process, checking 28 and 44, all of which fail. He then identifies 4 as a common factor and checks if it divides all numbers, finding that it does. He concludes that the HCF is 4. The video then presents a third example: 'HCF (8, 11, 16, 20, 28, 44, 46)'. He identifies 8 as the pivot element and checks divisibility, finding it fails for 11, 16, 20, 28, 44, and 46. He then checks 11, which fails for 8, 16, 20, 28, 44, and 46. He continues this process, eventually finding that 2 is the only number that divides all the numbers in the set. He concludes that the HCF is 2. The video ends with a 'Thanks for Watching' screen.

The video systematically teaches a specific method for finding the Highest Common Factor (HCF) by using the 'Least Number' approach. The core concept is to start with the smallest number in the set and test if it is a common divisor for all other numbers. If it is, it is the HCF. If not, the process is repeated with the next smallest number until a common divisor is found. This method is demonstrated through three distinct examples, each increasing in complexity, to reinforce the concept. The video effectively uses on-screen writing and clear verbal explanation to guide the viewer through the logical steps of the algorithm, making it a practical tutorial for students learning about HCF.

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