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. Section 1 | Language (Hindi): भाषा, लिपि, ध्वनि, वर्ण, अक्षर, स्वर, व्यंजन, मात्रा और संयुक्ताक्षर, वर्तनी, वर्ण-विन्यास, अनुस्वार, अनुनासिक, चंद्रबिंदु और ‘र’ के रूप, शब्द, पद और शब्द-भेद, संज्ञा और सर्वनाम, विशेषण और क्रिया, लिंग, वचन, पुरुष और कारक, काल, वाच्य, वाक्य और वाक्य-भेद, संधि, समास, विलोम शब्द, पर्यायवाची शब्द, सामान्य अशुद्धियाँ, अनेक शब्दों के लिए एक शब्द, मुहावरे और लोकोक्तियाँ, अपठित गद्यांश और अपठित पद्यांश, Multi-Topic Content (Cross-Concept Material), वर्णमाला
  3. Section 1 | Language (उर्दू भाषा — 22 प्रश्न (निश्चित)): Spelling & Diacritics, Grammar (اسم, فعل, صفت, ضمیر), Vocabulary, Idioms & Proverbs, Comprehension
  4. Section 1 | Language (বাংলা / बांग्ला भाषा — 22 प्रश्न (निश्चित)): Bangla Script and Sounds, Bangla Grammar and Usage, Bangla Word Formation and Vocabulary, Reading and Text Interpretation
  5. Section 1 | Language (English): Vocabulary, Noun, Subject Verb Agreement (Verb Noun Agreement), Adjectives, Tenses, Pronoun, Verb, Adverb, Preposition, Articles, Determiner, Conjunction, Modals, Active Passive Voice (Voice), Direct and Indirect Speech, Sentence Correction (Error Correction), Sentence Completion (Fill in the blanks), Sentence Construction, Sentence Re-arrangements (Para Jumbles) (Narrative Sequencing), Comprehension / Reading Comprehension / Unseen Passages (Critical Reasoning) (Paragraph Questions), Cloze Test (Cloze Passage), Verbal Analogy (Word Based Analogy), Facts, Inference and Judgements
  6. Section 2 | Primary Maths & Reasoning: Ratio and Proportion (Ratios), Divisibility Rules, Mixture and Alligation, Permutation and Combination, Number System, HCF LCM, Sequence and Series (Series), Speed Time and Distance, Series (Number and Letter Series) (Numerical Relations and Reasoning), Coding Decoding, Non Verbal Reasoning (Spatial Aptitude) (Spatial Reasoning) (Visual Reasoning), Percentage, Average, Profit and Loss, Simple Interest and Compound Interest, Time and Work, Mensuration and Geometry, Age Problems, Arithmetic, Powers and Exponents (Surds and Indices), Algebra, Probability, Trigonometry, Syllogisms, Seating Arrangements, Blood Relations, Directions (Direction Test), Analytical Reasoning (Counting Figures Reasoning), Puzzle Solving (Puzzles), Calendar, Clock, Cubes & Dices, Venn Diagram, Data Arrangement, Inequality, Analogy, Ranking, Order and Sequence
  7. Section 2 | General Awareness (GK + Current Affairs): Polity, Physics, Biology, State Wise GK, Chemistry, History, Geography, Indian Economy, Environment, GK- Current Affairs, Static General Knowledge
  8. Section 3 | Computer System and Org. (CSO): Basics of COA, Floating Point Rep, Cache Memory Organization, Instr Formats & Modes, Programming the Basic Computer, Input Output Organisation, Register Transfer and Microoperations, Control Unit Design
  9. Section 3 | Database Management System: Basics of DBMS, ER Diagram, Relational Model & Functional Dependencies, Keys & Integrity Constraints, Normalization (1NF - BCNF), Decomposition Properties & 4NF, SQL, File Organization & Indexing, Relational Algebra, Relational Calculus, Transaction Management, Concurrency Control
  10. Section 3 | Operating System: Introduction to OS, Process Management, CPU Scheduling, Threads & Process Creation, Memory Management, Virtual Memory, Disc Scheduling, File Management, Process Synchronization
  11. Section 3 | Computer Networks: 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, Transport Layer Services, TL: Congestion & UDP, Application Layer, Hardware basics
  12. Section 3 | Data Structures: Introduction to DS, Array, Stack, Queue, Linked List, Tree, Graphs, Hashing, Algorithm Analysis, Time Complexity Analysis, Sorting Algorithms, Greedy Algorithms, Minimum Spanning Trees, Shortest Path Algos
  13. Section 3 | Theory Of Computation & Compiler Design: Introduction to TOC, Deterministic FA (DFA), Non-Deterministic FA, Regular Expressions, Grammar, Regular Language Properties, Moore & Mealy Machines, Pushdown Automata & CFG, Turing Machines, Intro to Compilers, Lexical Analysis, Grammar & CFG, Syntax Analysis: Top-Down, Syntax Analysis: Bottom-Up, Semantic Analysis & SDT, Intermediate Code Gen, Code Optimization
  14. Section 3 | Emerging Trends (AI, Societal Ethics & MS Office): Artificial Intelligence, Emerging Tech Trends, Society, Law & Ethics, MS Office Applications
  15. Section 3 | Software Engineering: Fundamentals of Software Engineering, Software Requirements and Quality Assurance, Software Design, Estimation and Metrics, Software Maintenance and Configuration Management, Software Testing
  16. Section 3 | C Programming: C Fundamentals, Control Flow, Functions, Arrays & Pointers, Storage Classes, Structures & Enums, DMA, Macros, Scoping & File Handling
  17. Section 3 | OOPS, C++, JAVA, HTML: OOPS with C++, Java, HTML Basics, CSS
  18. Section 3 | Java: Java Fundamentals, Array, String, IO & References
  19. Section 3 | Python: Introduction to Python, Tokens, Variables, Data Types, I/O, Operators & Expressions, Control Flow & Looping, Collections & Strings, Functions & Modules, File Handling & Data Analysis
  20. Section 3 | Digital Electronics: Digital Systems & Boolean Basics, Logic Gates & Hardware, Boolean Expression, Boolean Minimization, Combinational Circuit, Sequential Circuits, Number System, Number Representation
  21. Section 3 | Multimedia: Multimedia
  22. BPSC Previous Year Papers:
  23. BPSC Full Mock Tests:
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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